Level failed animations, walls and normal maps.

Support for Level Failed animation playback.
- Plays a random "failed" sound when you are detected and forced to respawn

Added wall textures and prefab
- Four different textures and one prefab

Added normalmaps for new and existing textures
- New materials are found under texture/Material
- Swap these in with the current materials used on your map

Added wall physics material
- No friction means you don't get stuck to walls while jumping or brushing against them on the ground
- Needs changes to player and floor physics to be implemented