build: add AST support

Change-Id: Id5f88dba528c7b48b1d3f059f9ec65b9e2a88ef5
Revert "build: add AST support"

This reverts commit 3b4f8b3deebe41e5d2b861a44f4352ac6aab2ada.

Change-Id: I1b2370de13470549952285e2c46b68a0a1f9cc97
Move emulator.mk out of full_base.mk

Instead we should have the emulator products (full, full_mips, full_x86,
sdk) inherit from emulator.mk directly, because full_base.mk is also
inherited by real device products, such as full_manta.mk.

Conflicts:
	target/product/full_base.mk

Change-Id: I6f5f9255c73be8a4cfad7ddf88c4b633b05a7091
build: Add support for PRODUCT_COPY_FILES_OVERRIDES

 * We may have a case where prebuilts need to be built from
   source instead based on an externalized config.
 * New directive takes a list of destination files to remove from
   PRODUCT_COPY_FILES so that other instructions can be supplied.

Change-Id: I7feff16440e54d1676ffddbbd96d5947efa43ede
Merge remote-tracking branch 'cm/cm-10.2' into cm-10.2-tonyp