Fix the threading for GL Context in Qt5.
Connect the emu_thread start/finish to a moveContext slot.
Fix EmuThread loop by ensuring it exits properly.
Note: There is a pre-existing issue with booting a new game in that it keeps the old EmuThread.
The GL code now supports this but the Core still doesn't.
Pass format to the QGLWidget and use atomic instead of mutex.
Merge pull request #75 from xsacha/qt5

Fix threading for Qt5.