Add shadows to the world

Ogre has quite extensive support for different shadow techniques, and it wouldn't be too hard to add shadows to Ember. There are of course a lot of different techniques available, everything from just dark decals below world entities to full texture shadows. Currently the best method seems to be texture shadows. There are however quite a lot of different techniques available. Any implementation would also need to work with the shaders used, preferably in a generic way. Nonetheless one has to assume that all shaders need to be extended with support for shadows.
In an initial phase we only need to support shadows on the terrain, but self shadowing as well as universal shadows would be nice in a further phase.
Another nice thing would also be to have the shadow system recognize when the performance drops and then adjusting the shadow system, either by decreasing the number of meshes that are shadowed, or by disabling shadows altogether.
We currently only have one light source in the world (the sun) but further on we'll probably add support for more light sources (fires, torches and so on). In an initial phase we only need to support the one light source setup however.
More info about the Ogre shadow system can be found here: http://www.ogre3d.org/docs/manual/manual_67.html#SEC286