Merge pull request #8 from Kaffeine/master

Tools/WorldUtils: Fix compilation.
World loading.
Fixed bug in TextUtils.
Debug variables removed.
Small refactoring in python scripts.
Legacy functions removed from libRanger.
Fixed some errors founded by static analyzer.
Tools are now using the stream API from libRanger.
InteractionContext moved to WorldObject tree.
All world styles moved to new StyleManager.
WorldSkinManager -> SkinManager.
Asteroids.
Meteor -> Asteroid.
Asteroid speed calculation.
New class SpaceObjectWidget that representing space object.
Fix building on Windows with MSVC.
Fix some bugs found on windows.
Fix building using non-MSVC compilers.
Fix some small bugs found when using clang.
Source tree refactoring.
New install scripts for headers.
Installation scripts for python package.