Merge pull request #16 from ImperatorPrime/master

AURORA: Fixed Compilation error.
COMMON: Make sure INT32_MIN and INT32_MAX are signed
AURORA: Add ResourceManager::blacklist()

A blacklisted resource will never be used.
ENGINES: Bump the base resource priority to start at 1

Because 0 now means blacklisted
NWN: Blacklist fnt_galahad14.dds, fixing Cyrillic fonts

This closes issue #15.
DOCS: Mention the wiki TODO page
GRAPHICS: Also do 16bpp video modes
MAIN: Make the target command line argument handling less ambigous

Now, if a non-existing target is specified together with a path,
xoreos will create that target.
DOCS: Mention the project wiki
NWN: Mark the "portraits" data directory as optional
GRAPHICS: Import updated YUV code from ScummVM

Bink and XMV now have improved contrast
DOCS: Fix a few small Doxygen issues
COMMON: Fix formatting on a bracket
AURORA: Add function for hashing strings in HERF files

Thanks to DrMcCoy for figuring out the hash function.
BUILD: Extend boost.m4 to recognize gcc 4.7 and 4.8
GRAPHICS: Properly initialize Cube::_rotation
AURORA: Fix a signed/unsigned comparison warning
GRAPHICS: Add support for RLE-compressed TGA images

Needed for some Sonic images
GRAPHICS: Fix formatting
COMMON: Add string hashing algorithms