Support for Roget's thesaurus from project Gutenberg.
	
Datafiles are (temporarly) in /n/sources/steve/roget,
roget and rogetindex are the data and index respectively.
/sys/src/cmd/dict/mkroget will rebuild build these
from roget-body.rtf (with the help of rtf2txt).
	
I suggest the data and index should go in /n/sources/roget
similar to /n/sources/pgw.
	
-Steve