Clean up full config - DO NOT MERGE

This splits the existing full.mk in two parts:

-One is the device-independent full_base.mk
-The other is the emulator-specific device.mk

This way we'll be able to inherit from full_base.mk
for on-device builds without any emulator-specific
files getting in the way.

Change-Id: Ieb1f4ed47988c8fff119ff53f1f374032da3752d