Optimize shadow map matrices (use 4x3 matrix)

Optimize the shadow map matrix generation matrix for directional
lights to use a 4x3 matrix. The shadow map transformation matrix used
in lighting passes has also been optimized to use a 4x3 matrix.

Add a seperate shader for spotlight (projection) shadow map
generation.

Signed-off-by: Harm Hanemaaijer <fgenfb@yahoo.com>
Add SIMD optimizations

Add a set of SIMD-optimized functions, using SSE extensions on x86
processors, primarily used when calculation large amounts of
dot product and matrix multiplication.

The internal format of the MatrixTransform class (4x3 matrix) has
been changed to row-major for more efficient multiplication. Other
matrix types are still internally stored in column-major order.

Reorganize the silhouettte edge calculation code using class
functions and provide optional SIMD optimization.

The SIMD support level is configurable in Makfile.conf.

Some disappearing shadow bugs are visible in the current version
which may be due to bugs in matrix multiplication optimzations
or the changes to the MatrixTransform class.

Signed-off-by: Harm Hanemaaijer <fgenfb@yahoo.com>