add CMake doxygen to build system, fix headers/footers
add doxygen file
Revert "add CMake doxygen to build system, fix headers/footers"

This reverts commit d42735960b2a04142b5cda1ac9d9ad290ae9c1bc.
use CMake to setup Doxygen build
Merge pull request #26 from firefly2442/doxygen-cmake

Add doxygen build system into CMake (just like SFML)