Re-enable use of CocosDenshion in SimpleGame
CocosDenshion build setup for Qt 5 (no-op implementation)

Right now, all operations are implemented as no-op, but
libcocosdenshion can now be built as shared library and used.
Implement CocosDenshion backend using QMediaPlayer

Music and effect playback works, effect playback is not
totally low-latency; we could implement our own decoding
and mixing using QAudioDecoder and QAudioOutput to get
buffering, preloading, looping and latency working well.
Rename Makefile to Makefile.linux

Qt 5's "qmake" creates a "Makefile", and this would overwrite
the Linux Makefile included in the repository.

If you want to build the Linux version of Cocos2D-X, use:

   make -f Makefile.linux <...>

instead of

   make <...>
Do not include Qt headers in CCApplication.h

This avoids name collisions with the extensions sub-project
where "slots" is used as attribute of a class ("slots" is
redefined in Qt headers).
Qt 5: Add support for building libextension
Qt 5: Build test application (Cpp/TestCpp)
Qt 5: System-wide installation of targets
Initial RPM packaging for Qt5