CMake build:

 - add linuxmint to the list of supported apt dist
 - minor refactoring
Exit gracefully if nose is not installed
and tell the user to install it!
TRAVIS: Use setup.py
Add a bunvh of physfs unit tests
Finish PhysFS tests
Revert "CMake build:"

This reverts commit deeb8d84d2f90c5322f7c1e6e567bdda96a0e7ce.
Merge branch 'develop'
Add tests for sfml and box2D TODO
Add minimal test who fail
First sfml test
Merge branch 'develop'
Fix confusing __repr__

Display microseconds to avoid confusion when doing tests
with low values
Fix VideoMode __richcmp__
Fix return value of key_repeat property
Add test for sfml/system and sfml/window
Travis: Fix X Server
Remove OpenGL related tests
Add a decorator to skip tests on travis
Add an option to skip tests on travis
Use the --travis option