Switch C compiler to the generic 'cc' (to use the default compiler, not necessarily GCC -- this is for systems that offer both GCC and Clang, and use Clang as default).
Added AES+GHASH implementation using AES-NI opcodes; also ARM-Thumb assembly for faster Montgomery multiplication on Cortex-M0+. Added selection functions for "default" implementations.
New Makefile structure; added compatibility with Windows + Visual C + nmake.