Add internal libjpeg-turbo library to be used instead of libjpeg

Unfortunately requires nasm - the netwide assembler -
http://www.nasm.us/

Upstream libjpeg-turbo is meant to be built with CMake on Windows but
thanks to our gcc-wrappers we are able to avoid that.

jpeg is kept mostly for platforms we are cross-compiling to. For now,
it's used also for Mac OS X because jpeg-turbo does not build there,
which should be fixed later.

Change-Id: Id87b7072a8acc2578c3abf7e82cb1499e5094dbf