add basic debugging macros

Hi,

I really like your idea with *Haywire* - I am looking forward to contributing some stuff.
While I was trying to add some debug/release build configurations (which failed because of my lack of *gyp* knowledge :-) ) I came up with some basic debugging macros. These could be helpful until you decide on some proper logging mechanism.

The macros are C89 compatible.

Cheers,
Gregor