Error handling and tests...
Added sbt plugin.
branch argument in PropsLoaderFactory.loadBranch was handled incorrectly.
== isn't !=
Merge remote-tracking branch 'upstream/master'

Conflicts:
	java/project/Build.scala
Plugins an dependencies update.
Versions everywhere!
Added ".branch" to branch String.
Hardcoded PropsLoader.branch to master.
Merge remote-tracking branch 'upstream/master' into php_props_loader
Props loader rewritten, some preliminary tests