Allow setting project name

[mzarnowski]

Previously, project name was derived from the targets used for importing it. Now, user can specify it when importing.

The import window looks as follows

And the resulting structure is:

The project view:

The name field is being automatically populated if and only if it was not changed by the user.

The strategy for generation of project name tries to mimic current approach (with a change of prepending the build root directory name). Since I don't have much experience with using the pants build tool, I could use some suggestions on how those automatically generated names could look like to actually useful.

[mzarnowski]

The four failures:

1) 
testModuleRunConfiguration(com.twitter.intellij.pants.execution.OSSPantsJvmRunConfigurationIntegrationTest)
  junit.framework.AssertionFailedError
    at junit.framework.Assert.fail(Assert.java:55)
    at junit.framework.Assert.assertTrue(Assert.java:22)
    at junit.framework.Assert.assertTrue(Assert.java:31)
    at junit.framework.TestCase.assertTrue(TestCase.java:201)
    at com.twitter.intellij.pants.execution.OSSPantsJvmRunConfigurationIntegrationTest.testModuleRunConfiguration(OSSPantsJvmRunConfigurationIntegrationTest.java:155)

 2) testScalaLibCompletions(com.twitter.intellij.pants.integration.TargetFileCompletionIntegrationTest)
  CompositeException (2 nested):
     [0]: java.lang.AssertionError: expected:<[scala_js_library(, scala_library(]> but was:<[scala_js_library(, scala_library, scala_library(]>
     [1]: com.intellij.testFramework.LoggedErrorProcessor$TestLoggerAssertionError: Editor of class com.intellij.openapi.editor.impl.EditorImpl hasn't been released:

3) testDependencies(com.twitter.intellij.pants.integration.TargetFileCompletionIntegrationTest)
  CompositeException (2 nested):
   ------------------------------
    [0]: java.lang.AssertionError: expected:<[examples/src/scala/org/pantsbuild/example/hello/exe:exe, examples/src/scala/org/pantsbuild/example/hello/welcome:welcome, examples/src/resources/org/pantsbuild/example/hello:hello, examples/src/java/org/pantsbuild/example/hello/greet:greet, examples/src/resources/org/pantsbuild/example:example, examples/src/resources/org/pantsbuild/example/jaxb:jaxb, examples/src/resources/org/pantsbuild/example:hello_directory, examples, examples/src/scala/org/pantsbuild/example/hello:hello, examples/src/resources/org/pantsbuild/example:jaxb_directory, examples/src/resources/org/pantsbuild/example/names:names, examples/src/resources/org/pantsbuild/example:names_directory]> but was:<[examples/tests/scala/org/pantsbuild/example:hello_directory, examples/tests/python/example_test/usethriftpy:usethrift, examples/src/java/org/pantsbuild/example/annotation/processor:processor, examples/tests/python/example_test/hello/greet:prep, examples/tests/java/org/pantsbuild/example/hello/greet:greet, examples/src/python/example:hello_directory, examples/src/protobuf/org/pantsbuild/example/distance:distance, examples/src/python/example:3rdparty_py, examples/tests/python/example_test:example_test, examples/src/java/org/pantsbuild/example/protobuf/distance:distance, examples/src/python/example/grpcio/server:server, examples/tests/scala/org/pantsbuild/example:example, examples/src/antlr/org/pantsbuild/example:exp_directory, examples/src/python/example:grpcio_directory, examples/src/java/org/pantsbuild/example/hello/main:main-bin, examples/src/python/example/grpcio/client:client, examples/src/resources/org/pantsbuild/example:names_directory, examples/tests/python/example_test:usethriftpy_directory, examples/src/python/example/hello/greet:greet, examples/src/python/example/grpcio/client:service, examples/src/scala/org/pantsbuild/example/hello/welcome:welcome, examples/tests/scala/org/pantsbuild/example:all_directories, examples/src/antlr/org/pantsbuild/example/exp:exp_antlr4, examples/src/antlr/org/pantsbuild/example/exp:exp_antlr3, examples/src/python/example/tensorflow_custom_op:tensorflow-zero-out-op-wrapper, examples/src/java/org/pantsbuild/example/annotation/example:example, examples/tests/scala/org/pantsbuild/example/hello/welcome:welcome, examples, examples/src/python/example:readme, examples/src/python/example/tensorflow_custom_op:tensorflow_custom_op, examples/src/python/example:pants_publish_plugin_directory, examples/src/resources/org/pantsbuild/example:jaxb_directory, examples/tests/java/org/pantsbuild/example/useproto:useproto, examples/tests/python/example_test/usethriftpy:usethriftpy, examples/src/python/example/hello/main:main, examples/src/scala/org/pantsbuild/example/hello/exe:exe, examples/src/java/org/pantsbuild/example/hello/main:main, examples/src/java/org/pantsbuild/example/annotation/main:main, examples/src/python/example:tensorflow_custom_op_directory, examples/src/resources/org/pantsbuild/example/jaxb:jaxb, examples/tests/python/example_test/hello/greet:greet, examples/src/python/example:example, examples/src/java/org/pantsbuild/example/hello/main:readme, examples/src/python/example/hello/main:hello-app, examples/src/python/example/pants_publish_plugin:pants-publish-plugin, examples/src/scala/org/pantsbuild/example/hello:hello, examples/src/antlr/org/pantsbuild/example/exp:exp, examples/src/java/org/pantsbuild/example/antlr3:antlr3, examples/src/python/example/pants_publish_plugin:pants_publish_plugin, examples/src/resources/org/pantsbuild/example/names:names, examples/tests/scala/org/pantsbuild/example/specs2:specs2, examples/src/scala/org/pantsbuild/example/scala_with_java_sources:scala_with_java_sources, examples/src/python/example/tensorflow_custom_op:tensorflow-zero-out-op, examples/src/java/org/pantsbuild/example/java_sources:java_sources, examples/src/resources/org/pantsbuild/example/hello:hello, examples/src/antlr/org/pantsbuild/example:example, examples/src/java/org/pantsbuild/example/hello/greet:greet, examples/src/java/org/pantsbuild/example/hello/simple:simple, examples/src/resources/org/pantsbuild/example:example, examples/tests/python/example_test:tensorflow_custom_op_directory, examples/src/python/example:all_directories, examples/tests/python/example_test/tensorflow_custom_op:tensorflow_custom_op, examples/src/resources/org/pantsbuild/example:hello_directory, examples/src/python/example/grpcio/client:imports, examples/tests/python/example_test:all_directories, examples/tests/python/example_test:hello_directory, examples/src/antlr/org/pantsbuild/example:all_directories, examples/tests/scala/org/pantsbuild/example:specs2_directory]>
    [1]: com.intellij.testFramework.LoggedErrorProcessor$TestLoggerAssertionError: Editor of class com.intellij.openapi.editor.impl.EditorImpl hasn't been released:

4) testFilePathRelativeMacro(com.twitter.intellij.pants.macro.FilePathRelativeToBuiltRootMacroTest)
  junit.framework.AssertionFailedError
    at junit.framework.Assert.fail(Assert.java:55)
    at junit.framework.Assert.assertTrue(Assert.java:22)
    at junit.framework.Assert.assertNotNull(Assert.java:256)
    at junit.framework.Assert.assertNotNull(Assert.java:248)
    at junit.framework.TestCase.assertNotNull(TestCase.java:417)
    at com.twitter.intellij.pants.macro.FilePathRelativeToBuiltRootMacroTest.testFilePathRelativeMacro(FilePathRelativeToBuiltRootMacroTest.java:26)

Are exactly the same as those in #483 (https://travis-ci.com/pantsbuild/intellij-pants-plugin/jobs/279379516) so I believe they are not related.

[wisechengyi]

This is great, thanks @marek1840!