Released v1.12.0

Two bugs has been fixed, both non critical:
- returncode.h: old mislooked bug: RCD_RETURN_FALSE() returned RCD_TRUE! The only reason that this Bug have survived for a so long time is that true/false values of rcode was never used be me until now. Anyway, this has ZERO influence on the libcxc behaviour.
- locally aliased funcions: missing "hidden" attribute - discovered during investigating the asm code: now all the locally aliased functions are called without the use of PLT table -> faster.