WyIL: Bug fix for AttributedCodeBlock

Source line information was being lost because of a bug in
AttributedCodeBlock which was being used by the CodeGenerator.  Also
because of another bug in the constructor, code indices weren't being
correctly generated.
WyIL: Bug fix for WyilFileReader

The WyilFileReader was not correctly handling the reconstruction of
labels from a WyIL file.  This is because it was not taking into account
the nested structure of bytecodes.  However, now it is :)
WyJC: Removed Primitive Type Optimisations

There were some optimisations in the WyJC backend whereby some types
(e.g. bool, byte, char) were being coded into primitive java types.
However, with the elimination of the back propagation phase this becomes
problematic (at least for now) since it requires significant extra
machinery to ensure proper coercions are inserted.
WyJC: Still Removing Primitive Type Optimisations

Updating the utility functions.
WyJC: Still removing lots of interesting ops!
WyJC: Continued fixing primitive optimisations.