Support for disabling waffles runtime

All waffles will now support being en/disabled during runtime through a header
X_WAFFLEHAUS_*classname_uppercase*_ENABLED.

Similarly they support having themselves toggled between testing/not testing
with X_WAFFLEHAUS_*classname_uppercase*_TESTING.
Merge pull request #51 from roaet/runtime_reconfigure

Support for disabling waffles runtime