Adds some more properties to the "sobel" edge detector shader and cleans up some other post-processing related things.
Fix for StringMap serialization.
Merge branch 'develop' of https://github.com/MovingBlocks/Terasology.git into develop
Tweaks various rendering related things and adds a new custom (less repetitive) ocean/water simulation/animation algorithm.

- Adds that the normals for the offset water vertices get calculated using multisampling and differentiating
- Separates grass animation from water animation (water animation is only available via the "Insane" and "Epic" graphics quality settings from now on)
- Adds various properties to control the water simulation
- Adds support for different quality settings for the water simulation (octaves used for the wave generation can he varied)