Use unsigned integers for material effects

This generated a run-time error on NVIDIA.
Correction how "flat" keyword is used

This generated an error on NVIDIA.
Improved SSAO

Still rather costly on the GPU.
Remove access to normals from SSAO
Change depth into a texture

The plan is to use the texture as input for some shaders.
Shadow map bluring shall not use depth test
Improved comments.
Blur the lighting to make softer shadows
This is a little costly, so it is only supported for high performance systems.
In OVR mode, do not use mouse for pitch control
The pitch is automatically controlled as a function of the camera distance.
Disable the fatal error for missing shader parameters.
Compute world distance using depth texture

Extend the uniform buffer with data for clipping planes.
Make SSAO use depth texture instead of G-buffer for distance
Move poisondisk to common.glsl

Remove it from some places it wasn't used.
Enable SSAO

It is now efficient enough.
Clean up unused position texture on SSAO
Use correct shader syntax for initialized arrays
Base SSAO on angle instead of sample distance difference
Remove unused binding of render buffer
BaseDialog destructor removed

It was used to verify that there was no dialog. But that is not valid if
the game is closed with a dialog open.
Removed several header files not neded.
Added debug messages.
Remove warning
Detect caves and add watery walls

This is done by looking for stone in a number of directions. If it is
found in enough directions, we assume it is a cave.
Make _angleHor and _angleVert local.

All global references should use Model::gPlayer.fAngleHor and Model::gPlayer.fAngleVert.