[osx/ios] - adapted readmes - building python module pil isn't needed anymore (will be handled by unified depends in the future - wip)
depends: fix pil build with zlib

Its "build system" is clueless, so rather than jumping through hoops to help
it find zlib, we'll just assume zlib as a hard dependency
depends: add pil to default depends, and add freetype as a dependency
depends: remove python pil helper scripts and docs, they've been moved to depends
depends: nuke old darwin depends
depends: nuke old android depends
depends: update android docs to point at unified depends