Merge pull request #85 from Ghabry/development

Remove BMP size check and remove transparency from system bg
Update Makefile.am
Check for pkg-config, pixman, freetype, png and jpeg, remove sdl_image and sdl_ttf.
Add include path for shinonome.hxx.
Merge pull request #89 from fdelapena/master

Update autotools
8bit PNG: RPG Maker always uses palette index 0 as transparent color