Added various primitives for checking types.
Added missing argument to the adt type constructor.
Added support for descendant matching (partially working).
Merge branch 'master' of https://github.com/cwi-swat/rascal.git

Conflicts:
	src/org/rascalmpl/library/lang/rascal/grammar/definition/Symbols.rsc
moved java specific m3 models to lang::java
added rudimentary URI resolver for java uris as produced by Ashim's JDT
to m3 converter
Merge branch 'master' of git@github.com:cwi-swat/rascal.git
Added 'isNonTerminalType' check on symbols.
Added a production type to the type checker.
Major code reorganization
- Split primitives in RascalPrimitives and MuPrimitives.
- All MuPrimitives are inlined in the RVM interpreter.
- Added instruction muCallMuPrim
Merge branch 'master' of https://github.com/cwi-swat/rascal.git
Productions in the store have now production types; productions with
unlabeled symbols are now also added to the store.
Merge branch 'master' of https://github.com/cwi-swat/rascal.git
Extended the prettyprint facility of the type checker with non-terminal,
terminal and regular symbols.
Added computation of the 'nonterminalFields' part of the configuration
returned by the type checker.

- certain functions, e.g., equivalent, etc., still need to be defined
for the non-terminal symbols.
fixed issues in symbol printer. 
added convience function to parse tree to access the builtin symbol
printer
Merge branch 'master' of git@github.com:cwi-swat/rascal.git
Merge branch 'master' into rascal-to-jigll