Use preprocessor so helper files are more likely to compile

Consider the case where a project has multiple processors: one processor supports 64-bits, and a different one does not. These two processors will need different versions of the helper files (i.e. for 64-bit support). This makes organizing the output files more complex, since the helpers must be generated twice in two different locations.

A more flexible solution would be to bracket 64-bit code (for example) with pre-processors that are used to determine if the compiler can handle that code. That way one set of helper files could support both processors.

billvaglienti / ProtoGen

Use preprocessor so helper files are more likely to compile #21