Merge pull request #71 from benkasminbullock/master

Add getters to the library
Merge pull request #73 from benkasminbullock/master

Documentation of getters
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Carefully select include dirs to avoid png.h/libpng version mismatch
Removed Perl file
Simpler INT_MAX math
Use custom allocators for everything
Custom allocator for aligned memory
Formatting
Hidden accidentally-exported function
Sign comparisons
Manual updates
Check pointers
Return values from getters directly rather than via pointer
Convert images to sRGB using lcms1
USE_LCMS=1
libpng types in LCMS, formatting
Embracing bracing
Avoid arithmetic on void*