Log Message:
Update to 0.24

Upstream changes:
0.24  Sat Jan 10 00:45:34 MST 2015
	- simplified shabits() routine (bitwise input buffering)
		-- slightly less efficient but easier to understand
	- minor documentation tweaks and additions

0.23  Sun Jan  4 05:36:30 MST 2015
	- updated to reflect Draft FIPS 202
		-- append domain separation bits to message
		-- implement SHAKE128 and SHAKE256 Extendable-Output
			Functions (XOFs)