[ot] Prefer Windows platform cmap tables / accept all Unicode encodingIDs

Some fonts on the Mac ship with (0,1).
[arabic] Allow disabling win1256 fallback code

By defining HB_NO_WIN1256.
[arabic] Don't #include __FILE__

Fine!

https://code.google.com/p/chromium/issues/detail?id=406957
Fix build
Merge branch 'master' of git://github.com/behdad/harfbuzz