$ cp ~/current/2009/python-hvector-data/data/flag/[IJ]* linhomy/_data # For issue10.
For #10 start data.py, add _DATAPATH attribute.
For #10 add data.read_data(template, *argv).
For #10 add data._cache with IC-word values.
For #10 make start on J(a,b) in data._cache.
For #10 add and use data.j_twiddle, to get J entries symmetric.
For #10 get 'J(C,IC)' etc working - but tidy and testing needed.
For #10 tidy and test 'J(C,IC)' etc.
For #10 add missing files J-0-flag.txt and J-1-flag.txt (and revise tests).
For #10 fix special case ic_word has only 'C' in it.