Re-add ARCH_ARM_HAVE_TLS_REGISTER for armv7

OpenGL needs this flag for armv7

For more information :
https://github.com/androidarmv6/android_bionic/commit/7bc88df02f887229738b08fd7f7bd2668805f306
https://github.com/androidarmv6/android_frameworks_native/commit/4ffa795a3e9f2d2a26766147b1cfedbe78e823d4

Change-Id: Ib68c17e2f8dd3c8c15f8f3ea235fe25a46d05b6a
add support for overriding build.prop settings.

Change-Id: Ie4224d608b7bcb0c2087bd77bc954f8f5f9b6495
kernel.mk: Use standard toolchain paths

Change-Id: I1225fd05dcedcff03a1cf1102841cbd010b609cf
build: recovery: don't remove init.*.rc

Change-Id: Ic1e14e1e82cb28106da5b39f530e0b667377840d
Fix building custom recovery with userdebug

Credit Koushik Dutta

Change-Id: I41f1a91849f3aab435a3398696149afce68d8708