Added functionality to keep track of the current visit context, including a new library to access the information at runtime
Merge branch 'master' of github.com:cwi-swat/rascal
Merge branch 'master' of github.com:cwi-swat/rascal
Added the 'Run' button.
New 'RETURN_0' and 'RETURN_1' instructions.
Fixed a stack pointer bug in execution of CALLDYN in case of closures.
Another test example.
Added checks ton undeclared labels.
Merge branch 'master' of https://github.com/cwi-swat/rascal.git
Added check that current pc value is in legal range.
Added a IValueFactory argument to constructor of CodeBlock (anticipating
different treatment of constants).
Replaced coroutine START instruction with INIT and changed its
semantics.
Merge branch 'master' of https://github.com/cwi-swat/rascal.git

Conflicts:
	src/org/rascalmpl/library/experiments/CoreRascal/RVM/Examples/CountDown_b.java
Minor, forgotten thing.
Merge branch 'master' of https://github.com/cwi-swat/rascal.git
Changed constant handling to allow direct inclusion of PDB values in
instructions.

General code cleanup and name improvement.
Solved various minor problems.
Started with backtracking experiments.
Added file
Merge branch 'master' of https://github.com/cwi-swat/rascal.git
Added primitives.