Merge b2a51af from take-cheeze/master

fix expat url
libpng: Use run_autogen_build instead of manually configuring

I have a feeling that although the library built, it was probably broken
(1) Used autogen instead of configure right after running autogen
(2) Missing assignment operator '=' for --host
pixman: Fix config.sub path and don't hardcode PSPDEV path
squirrel: Remove obsolete leftover patch
pixman: Partially revert 9052ae6

I forgot I was running pixman.sh directly instead
of through libraries.sh and misunderstood the
location of the package sources.
Update zlib to 1.2.8

Now uses download_and_extract and apply_patch instead of psp-ports's
pre-patched sources which are hard to maintain.
Update bzip2 to 1.0.6

Now uses download_and_extract and apply_patch instead of psp-ports's
pre-patched sources which are hard to maintain.
libpng: Fix build and split patch from source

Now uses download_and_extract and apply_patch instead of psp-ports's
pre-patched sources which are hard to maintain.
Merge pull request #20 from Bracket-/misc

Miscellaneous cleanups/fixes and updates