add clutter-gst Formula with --enable-introspection

Add `clutter-gst` Formula with --enable-introspection.
In OSX, vanilla clutter-gst causes compilation failure.
So, I applied patch that almost same as: https://github.com/TrickPlay/osx-ports/blob/master/graphics/clutter-gst/files/patch-clutter-gst-clutter-gst-video-sink.c.diff
And, I add addtional OpenGL framework reference.