Make code more readable.
Fix wrong collisions of up-right and down-left diagonal jumpers.
Fixing diagonal jumper collisions (not working yet).
Merge branch 'master' of github.com:christopho/solarus
Merge branch 'master' into jumper

Conflicts:
	src/entities/Jumper.cpp
Fix infinite call and obstacle detection of jumpers.
Still working on jumpers.
Fix jumpers that could be traversed sideways. Fix #481.
Merge pull request #482 from Nate-Devv/master

Install documentation changes (added gcw-zero based on openpandora instr...
Don't refcount the hero from HeroSprites.

This introduced a memory leak because of a circular refcount dependency.
Fix compilation error in Grid instanciation.
Fix memory leaks with tiles.
Fix musics stopping playing sometimes on slow machines.
Readded stream documentation.