build: Set ccache base to build top

This enables ccache sharing between different build tree paths.

Change-Id: I99636bdd2779a6ccf0649f027e35cf67df44b6ae
build: Add new public keys to recovery

Change-Id: I11dea464297813be36e60c23728dde8893535c46
Merge branch 'cm-11.0' of github.com:CyanogenMod/android_build into cm-11.0
build: Include an extra device.mk

Change-Id: I4373f78f57c81e46affc2f6a6bc854bf4c3d00db
Merge branch 'cm-11.0' of github.com:CyanogenMod/android_build into cm-11.0
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
Merge branch 'cm-11.0' of github.com:CyanogenMod/android_build into cm-11.0
Merge branch 'cm-11.0' of https://github.com/temasek/android_build into HEAD

Conflicts:
	core/combo/select.mk

Change-Id: I3f9784c519d47e7f6fb4f1835a61eba88e866303