Generate extra userdata partition if needed

* To support variants of devices which may come in 16/32/64GB variants.

Change-Id: I74c32d8316f0450a1445fe95a95e5cabb7a9dd1b
Fixed building incrementals when "no separate recovery" is specified.

Change-Id: I1d7add44554ebc4b68dc09debdd0c0fb229061a9
core: arm: Add support for GCC 4.8 and 4.9

Change-Id: I96bffffb4b0e16ef5bcedc85dedc70ca3dc2182f
core: arm: Use -O3 optimization inside TARGET_arm_CFLAGS

Change-Id: I224b62b3dada874d00a90258a1dcffcea09bc029