Added x86-64 assembly implementations of Keccak-f[1600]
Added support for Keccak-f[800] and reference implementation
Added support for Keccak-f[400] and reference implementation
Added support for Keccak-f[200] and reference implementation
Added ARM assembly implementations of Keccak-f[200, 400 and 800]
Added AVR8 assembly implementations of Keccak-f[200 and 1600]