Use a display list for the OpenStreetMap tiles.
Removed unneeded include.
Added DemoPlayer class and methods to play back some silly music.
Give the DemoPlayer a pointer to the GLWidget. Adding track files to the app bundle as resources.
Added GLWidget::recenter. Make sure the MainWindow destructor gets called on app exit.
Added a method to pre cache tiles. MainWindow now owns the tile source. Turned off memory cache cleaning because performance is the priority. Precache 1800 tiles.
Merge branch 'demoparty' of github.com:dal/RunParticles into demoparty

Conflicts:
	src/DemoPlayer.cpp
	src/DemoPlayer.h
	src/MainWindow.h