some results from looking at the WCTBinary tree

- ASCII space visible in high-occupancy contexts
- scrambling makes the compression ratio worse
proof by "I think so":

Bit len of encoded str with WCTPhases is the product of the pw-s at the
root, for all the phase trees.
some results for WCTPhases with scrambling; no obvious conclusion
Merge branch 'master' of github.com:cberzan/ctw
finish implementing enc_len_phases(), and --debug
function to add an extra bit to each byte, causing misalignment
script to run experiments