Functions to get enums added to Core.rsc

Started adding M3 code to handle enums. There actually is a special type for them!
Changed debug output

Working out a few kinks.
Fixed some String stuff
Some more minor String fixes. All tiny output mismatches with the master branch should now be solved.

Note that the visitor version now outputs enums as the M3 for src does; using java+enum and java+enumConstant. This has not yet been ported to master. Can be done later/if needed.
Improved enums
Cleaned a bit of code.

Rascal Crawler should be fixed now! :D
Added functions to Core.rsc to get enums.

Rascal Crawler should now be fixed.