Modified Doxyfile to generate PHP files for website
Fix CMake file: use PHP files
Rename output doc dir to 'php'
Add doxygen css to header
Fix php footer include
Test with extra div
Don't overwrite doxygen css
Fix relative links
Fix Doxygen rules to support both local and website documentation
Merge branch 'PHPDoc'

* PHPDoc:
  Fix Doxygen rules to support both local and website documentation
  Fix relative links
  Don't overwrite doxygen css
  Test with extra div
  Fix php footer include
  Add doxygen css to header
  Rename output doc dir to 'php'
  Fix CMake file: use PHP files
  Modified Doxyfile to generate PHP files for website