Overlay support for legacy camera libs

Move http://review.cyanogenmod.com/#/c/13285/ to proper place for jellybean.

1. Rename OverlayHtc to Overlay in file names
2. Use BOARD_USES_LEGACY_OVERLAY to enable

Signed-off-by: Evan McClain <aeroevan@gmail.com>
Change-Id: Ib6afd1b610b1d3e263fcaa38585e7a1116baaf58

Conflicts:
	libs/ui/Android.mk
MemoryHeapBase: ifdef for gingerbread/froyo compatibility

Allow to "revert" by a board config flag the offset member addon
see commit f24c4cd0f20 (aosp change id Ie618fb5c0718e)

This change is required to use overlay based proprietary camera libs
coming from gingerbread and froyo builds.

This change also requires a global cflag named BINDER_COMPAT
because a lot of modules use the MemoryHeap includes

Add this in your BoardConfig.mk :
COMMON_GLOBAL_CFLAGS += -DBINDER_COMPAT

Backported from /#/c/13317/

Change-Id: Ic8e18bc60a7310b0fa90ad251381e9f7d9e58d5e