Add custom stylesheet for documentation generated by doxygen.
Add obs logo to be used with doxygen.
Add custom header for doxygen.

We use a custom header to add source sans pro.
Add doxygen configuration file for obs.

This will currently only generate documentation for libobs.
Some documentation improvements in obs.h

A stub for the main documentation page was created.
Some documentation improvements in obs-properties.h

Create a stub for the documentation page.
Some documentation improvements in obs-module.h
Some documentation improvements in obs-source.h
Some documentation improvements to obs-service.h
Some documentation improvements to obs-encoder.h
Merge pull request #287 from fryshorts/doxygen

Add Doxygen configuration for creating api documentation