SRAMP-531 SRAMP-580 Server-side auto-detection of artifact types, replac...

...ed "expander" concepts
@objectiser & @EricWittmann, this is a decent example of what's possible.  It checks for the existence of switchyard.xml to "detect" a SY app archive.  Expansion is...expanded...to allow Java classes to be uploaded, but only if 1.) switchyard.xml references them or 2.) there is no switchyard.xml (see the note).