Added C support

[B0bby321]

The original author/authors did an amazing job creating this library for python. It is easily the best one I've seen. I was working on a C program that needed the cryptonight hash function, and stumbled across this library. The only problem was that I couldn't use it because of the python hooks. I changed up the cmake file so that there is now 2 more options: MAKE_CLIB_STATIC MAKE_CLIB I tried to preserve the original make file so that it does not interfere with the python lib that can be generated. The header cryptonite_hash has the macro flag CLIB that choose between the function needed for the C library and the function originally defined by the author. I hope this small change will be added to the project because it would be of great use to other C and C++ programmers.

Happy to take any criticism, always trying to improve