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.