build: Set ccache base to build top

This enables ccache sharing between different build tree paths.

Change-Id: I99636bdd2779a6ccf0649f027e35cf67df44b6ae
Merge "build: Set ccache base to build top" into cm-11.0
Don't set CCACHE_BASEDIR if its already set

 * enable use of shared ccache

Change-Id: Ic708a5d5169291d674b167aa2c87bf2c8adaafae
ota: Generate recovery-from-boot.p file

This may be wanted to update the recovery with system updates

Change-Id: Iacd41be7a8018cbc08b2606485d446756910f506
Merge remote-tracking branch 'cyan/cm-11.0' into cm-11.0