A collection of doxygen documentation comments.

Edits and updates are encouraged.

Instructions here:

https://github.com/openframeworks/openFrameworks/wiki/openFrameworks-doxygen-documentation-style-guidelines

These are not perfect, but represent significant progress accomplished over the weekend.  We encourage the oF team to quickly integrate these after the 0.8.1 release and apply edits corrections and continue filling in missing parts over the coming months.

Contributors were encouraged to _not_ modify the code itself in any of these commits, so the commits are primarily limited to comments and, in some cases whitespace / style updated to facilitate the comments.