Replaced deprecated (since ARMv7) data memory barrier with __sync_synchronize.
[android] Updated Android build scripts to use NDK r9 and GCC 4.8 to compile mono for ARM and x86
Merge pull request #175 from hkr/unity-4.5-staging

Cherry-picked update of Android toolchain and memory barrier implementation for Unity 4.x
Merge pull request #176 from Unity-Technologies/unity-4.5-staging

Android compiler update to GCC 4.8, replaced ARM memory barrier inline asm with __sync intrinsics