releasetools: allow devices to specify a custom make_recovery_patch

Change-Id: I891660c1bf919b369afd4ff496fb6bab85dffe3f
glibc: switch to Google's 4.8 host version

Change-Id: I43b70bb91e9e65d10e8b47673997cd76a9b917c7
Merge remote-tracking branch 'cyanogen/cm-12.0' into HEAD