add dirstate._dirtypl variable
Theoretically, it's possible to forget modified dirstate
parents by doing:
dirstate.invalidate()
dirstate.setparents(p1, p2)
dirstate._map
The final access to _map should call _read(), which will
unconditionally overwrite dirstate._pl.
This doesn't actually happen right now because invalidate
accidentally ends up rebuilding dirstate._map.
Basic install:
$ make # see install targets
$ make install # do a system-wide install
$ hg debuginstall # sanity-check setup
$ hg # see help
See http://www.selenic.com/mercurial/ for detailed installation
instructions, platform-specific notes, and Mercurial user information.