Added the interpreter, unit tests and shell script (wyopcl).
Merge pull request #457 from samminweng/master

Added the interpreter, unit tests and shell script (wyopcl).
WyCS: Removed generated files.

These two files are automatically generated and should not be included
in the repository.  They were added by accident during the merge of
Sam's interpreter, so I'm just removing them again now.
WyIL: Minor tweaks to interpreter