Add raspi option to configure script
Some stub code for an rpi winsys
Fix assert when setting custom EGL parameters
Clean up raspi renderer init
Reorder functions to put the finished ones at the top
Add methods to add/remove element from Dispman
Use new methods to add element to dispman. Fix an error in dispman_add_element(). The demo cogl_hello works
Refactoring to remove a bit of code duplication