Added Description Setter Plugin support

Author: kshtsk

docs/Job-reference.md

@@ -130,6 +130,7 @@ freeStyleJob(String name) { // since 1.30
         ant(String targets, String buildFile, String antInstallation,
             Closure antClosure = null)
         batchFile(String command)
+        buildDescription(String regexp, String text) // since 1.31
         conditionalSteps(Closure conditionalClosure)
         copyArtifacts(String jobName, String includeGlob, Closure copyArtifactClosure)
         copyArtifacts(String jobName, String includeGlob, String targetPath,
@@ -2375,6 +2376,14 @@ batchFile(String commandStr)
 
 Supports running a Windows batch file as a build step.
 
+### Build Description
+```groovy
+buildDescription(String regexpStr, String descriptionStr)
+```
+
+Set build description based upon a RegEx test of the log file, as a build step.
+Requires the [Description Setter Plugin](https://wiki.jenkins-ci.org/display/JENKINS/Description+Setter+Plugin)
+
 ### Gradle
 
 ```groovy

job-dsl-core/src/main/groovy/javaposse/jobdsl/dsl/helpers/step/StepContext.groovy

@@ -34,6 +34,14 @@ class StepContext implements Context {
         }
     }
 
+    void buildDescription(String regexpStr, String descriptionStr) {
+        NodeBuilder nodeBuilder = new NodeBuilder()
+        stepNodes << nodeBuilder.'hudson.plugins.descriptionsetter.DescriptionSetterBuilder' {
+            'regexp' regexpStr
+            'description' descriptionStr
+        }
+    }
+
     void gradle(@DslContext(GradleContext) Closure gradleClosure) {
         GradleContext gradleContext = new GradleContext()
         ContextHelper.executeInContext(gradleClosure, gradleContext)

job-dsl-core/src/test/groovy/javaposse/jobdsl/dsl/helpers/step/StepContextSpec.groovy

@@ -37,6 +37,19 @@ class StepContextSpec extends Specification {
         shellStep.command[0].value() == 'echo "Hello from Windows"'
     }
 
+    def 'call buildDescription method'() {
+        when:
+        context.buildDescription('[version] (.*)', 'foo \\1')
+
+        then:
+        context.stepNodes != null
+        context.stepNodes.size() == 1
+        def descStep = context.stepNodes[0]
+        descStep.name() == 'hudson.plugins.descriptionsetter.DescriptionSetterBuilder'
+        descStep.description[0].value() == 'foo \\1'
+        descStep.regexp[0].value() == '[version] (.*)'
+    }
+
     def 'call gradle methods'() {
         when:
         context.gradle('build')