Rearrange YAML Syntax def: Hook into yaml dumper instead of using regexps

This method is way safer than running regexps on everything and faster (and
even easier to configure).

Other:
- Change "[AAAPackageDev]" debug prints to only "[PackageDev]".
- Fix exception when calling `RearrangeYamlSyntaxDefCommand.status` because
  "sublime" module was not imported.
Add a (weird) test file for testing the javascript comment stripping

I had this on my drive anyway so why not just add it to the repo.
Rearrange YAML Syntax def: Insert newlines between pattern entries