Added Decode64 to start speeding up these bitwise operations when
encoding variable length numbers
Switched to Word16 for many binomial operations to make bounds clearer
continued refining RRR in an initial attempt to try to get rank working
fixed logBinomial
fixed RRR rank and (!)
Cleaned up RRR's builder
inlined builder and adjusted formatting
INLINE all the things
Added a decoding module to make it easier to work with various codes