XD-784 - Fixes for Windows compatibility
- Added blank line EOF at gradle.bat
- Fixed tests
Fix JsonStringToObjectTransformer's toString()
- Added pattern matching to replace linefeed '\n'
  incase of non-windows environment
Fix compile warnings
Add Mail Sources
Add Mail sink; externalize mail props
Add Mail test fixtures
Tidy up tests, add MailSink support
Add test support for imap idle
Fix GreenMail classpath issue

Also fix Generics warnings