Dropping support for SDL blitter

For those of you that are on IRC this may not be a surprise: we have decided to drop support of the SDL blitter in favor of Pixman. Why? Basically because SDL lacks a number of features and doesn’t work well with pixel alpha + surface alpha. Pixman is the software renderer fallback that XRender uses and it has been tested for quite a while, so it is solid. It also provides support for SMID accelerated proccessing through MMX/SSE2 (x86), Altivec (PowerPC) and NEON (ARM).

This implies that we’re effectively losing two dependencies (we lose SDL_ttf, SDL_gfx and SDL_image, and add pixman). If you got any questions regarding this, just ask here.