grep: display correct user/revision for --all in reverse.
Also handle multiple occurrences of the same line by storing
linestates in an array instead of a dict, and using difflib
to compute the difference between linestates.
#!/bin/shhg initmkfifo phg serve --stdio < p &P=$!(echo lock; echo addchangegroup; sleep 5) > p &Q=$!sleep 3kill -HUP $Pwaitls .hg