Added OGPL / PGO theme to PHP Variant
Updated English and French home page to include links to OGPL/PGO version of theme.
Updated English and French OGPL/PGO home pages to reflect the OGPL theme instead of GC Usability theme.
Removed one "de" in "Thème de de la PGO"
Merge pull request #47 from michael-milette/master

Added OGPL / PGO theme to PHP Variant