Replace tabs with spaces
Add more documentation to TextureFilters.cpp for gles2rice
Clean up combiner.cpp and combiner.h for the RICE plugin.
Fix a possible resource leak in TextureFilters.cpp for the Rice plugin.
Don't crash when invalid hires image was tried to load
Crop overlarge hires texture like Glide64
Texture packs developed with the focus on Glide64 seem to use too large texture
from time to time. Glide64 crops these textures correctly before they get
replaced.

Rice tend to just drop these textures. Cropping them in this context seems to
be more appropriate.
Use libpng to do load images as full (A)RGB images
The pngrw functionality for loading PNG files failed to load many texture
images because it didn't expect the bit depth and similar parameters. Rice only
needs 24/32 bit png files and therefore it is good enough to use the libpng
functionality to load all files as (A)RGB images.
Ignore size and fmt in CRC to be able to load textures for Glide64
Glide64 ignores the fmt and size information stored in the name of the hires
texture when searching in its index of textures. Rice instead replaces the two
lower nibbles of the crc32 with the size and fmt information. This causes
problems when Rice tries to load texture from texture packs made especially for
Glide64.

The behavior of Rice is changed to find texture like Glide64. The option
LoadHiResCRCOnly can be set to False to restore the old behavior
Speed up initial png info loading by not loading the entire content
The loading of PNG files is usually CPU bound. This is caused by the filters
and compression used to reduce the size of the file. This operations aren't
necessary when the content is dropped directly after reading the image.

Only loading the PNG headers makes the loading of a complete hires texture
set nearly instant when the I/O is not limited.
Enable link time garbage collection when link time optimization is enabled
Use the found hires filename instead of regenerating it on load time
Hires textures in Glide64 can have fmt and size set to a wrong value and still
get loaded. Rice has to store the name of the filename when it got found to
allow it to load such wrong named textures. Otherwise it is part of the index
and on load it will fail to find the file again.
merged heads
merged heads, fixing conflicts in src/TextureFilters.cpp