Try the possibility to import ipython libs
Complete restructuration of the project for allowing multiple backends
First window and display with the SDL2 library
Put exceptions in right place
Add adefault background color
Clean the code and remove call to widget in Qt killing the event loop
Add the management of the events for manipulating the scene
Correct OpenGL viewport problem
Don't pass events to windows if the event isn't for them
Handle case where no window is in the list
Merge pull request #9 from Acanthostega/SDL2

Integration of SDL2 for backend and hook for ipython event loop integration