improve the soundmanager and background sound
- make background sound non-3D
- fixed some bugs
- insert comments
Merge branch 'master' into fmod_integration
Merge remote-tracking branch 'origin/master' into fmod_integration
set comments to coding standard
Update README.md
Merge pull request #24 from lanice/fmod_integration

Fmod integration
Merge remote-tracking branch 'origin/master' into landscape_14
use typesafe enum class for TerrainLevels, iteration with initializer_list #14