Update backuptool.functions to M1

Change-Id: I8a7aab8dbb7dff3b54209e4838c5de5137354b0d
cm: Remove legacy compcache stuff

 * Remove all this stuff.  If a device wants ZRAM, it should be
   enabled by the maintainer and properly configured and tuned.
 * This stuff currently causes a conflict with the ZRAM support
   added in Kitkat. Kill it.

Change-Id: Ib2488ea4463e32ec44b65fe786f732145b5b6e23

Conflicts:
	config/common.mk