The final FIPS 202 SHA-3 standard mandates the prepending of a
01 suffix to the message prior to padding, which the original
Keccak submission did not specify. This change adjusts all
sha3 wrappers to behave standard conforming, and adds an optional
keyword argument raw-keccak-p to specify the original treatment.
Fixes#2.
The superfluous last iteration when start = end wasn't harmful, since the
iteration body winds up as a no-op in that case anyway, but wasn't
intended or needed.
Calls to sha3-update that did not completely fill an already partially
filled buffer were handled incorrectly, in that the buffer-index wasn't
properly updated. Thanks to Orivej Desh for the bug report.
