add global -Wno-unused-parameter to make gcc 4.8 happy

Change-Id: I58b163ce1221ec08d71b76e19fa69d369550dded
always rebuild build.prop

Change-Id: I9a6f4706cdc3e0ca4e40acb1b00419d72a236f65

Conflicts:
	core/Makefile
bring back squisher (2/2)

This reverts commit 9e215451006657b1a6de26f83924e207ede99114.
Revert "Include drawables for all densities - b/11270325"

This reverts commit 0068d25b4895162993118fe3b61d2775fa575e70.
include email package

Change-Id: I8a639258120d692b925335e791b875ce5ec25dbc