Fixed JSON array ordering when using JsonApprovals

closes #682 #667

DateScrubber enhancements

new factory methods to get DateScrubbers for sql.Date, util.Date and Timestamp

DateScrubber can handle Timestamp's toString()

Verify Map works with keys that are not comparable

Fixes #650

Added FileUtils.getResolvedPath()

When working with the file ./name.txt:

getAbsolutePath() will resolve this to /path/to/./name.txt

instead of the desired /path/to/name.txt.

getResolvedPath() solves this problem.

Python scripts for remove_abandoned_files and approve_all

Also, temp folder works when running tests in multi-threaded mode

ReadBuffer input no longer modifies newlines or adds them at the end

Also:
Added StringUtils.ensureEnding
Added FileUtils.readFile(file, ensureTrailingNewline = true)

Closes #637

Automatically git-ignore our temp folder

Just like ApprovalTests.Python, we now write a .gitignore file into our temp directory, thus consumers of the library don't have to add the folder themselves to their project's gitignore.

Once.runAsync

Once now supports running tasks asynchronously.

Bugfix

Downloading the approve_all script now is done asynchronously, meaning it won't affect build times.
Closes #615

Fixes problems with ReporterWithApprovalPower and FirstWorkingReporter

Fixes bug #446

Allow configuration of project base directory

By default, Approvals uses the working directory to find the working directory and its children to find source file and store received and approved files. This is now configurable if your working directory no longer contains the source. You can do this by setting either the system property or system environment variable called APPROVALTESTS_PROJECT_DIRECTORY. Here is an example of doing this when running tests with maven on forks:

<systemPropertyVariables>
    <APPROVALTESTS_PROJECT_DIRECTORY>${project.basedir}</APPROVALTESTS_PROJECT_DIRECTORY>
</systemPropertyVariables>

Reported in #608

Also fixes #612