* Adjust minimum filter radius for perspective
* Expand shadow frustum when camera FOV changes, reuse FOV distance adjustment from numeric.cpp
* Read shadow_soft_radius setting as float
* Use adaptive filter radius to accomodate for PSM distortion
* Adjust filter radius for texture resolution
Erase all traces of normal "generation" from fragment shaders
Remove the "feature" from the engine and default config
Remove any leftover documentation of it
the event header seemingly being generic with libevent thus renaming it.
openal and opengl are deprecated on newer mac os releases thus suppressing the build warnings.
Makes the liquid waving shader per-nodedef like waving leaves/plants,
instead of being applied to all liquids.
Like the waving leaves/plants shaders, the liquid waving shader can
also be applied to meshes and nodeboxes.
Derived from a PR by t0ny2.
