Added an action to register a compiler warning
Added warning class and integrated with action
Duplicate value detection

Implemented duplicate value detection. These are warnings only,
as duplicate values within enum definition are valid C/C++
Removed file attribute from warning class
Integrated generated warn.h and warn.cpp
Rudimentary implementation of tokens in warnings

Only #line is supported currently ...
Added dict member to warnings, and access methods.
Added operator[] to warning, updated warnings to use
Merged in #10 warnings