Tag generated classes as non CLS compliant.
Disable compiler warnings that are irrelevant for generated code.

These warnings are turned off:
CS0162:  Unreachable code detected
CS0219:  The variable '...' is assigned but its value is never used
CS1591:  Missing XML comment for publicly visible type or member '...'
Merge pull request #22 from rharrisxtheta/antlr-patchset-1

Small patches for minor compile issues in CSharp.stg