dirstate: rename forget to drop
It has substantially different semantics from forget at the command
layer, so change it to avoid confusion.
We can't simply combine it with remove because we need to explicitly
drop non-added files in some cases like commit.
This is a test of the wire protocol over CGI-based hgweb.
initialize repository
$ hg init test
$ cd test
$ echo a > a
$ hg ci -Ama
adding a
$ cd ..
$ cat >hgweb.cgi <<HGWEB
> #
> # An example CGI script to use hgweb, edit as necessary
> import cgitb
> cgitb.enable()
> from mercurial import demandimport; demandimport.enable()
> from mercurial.hgweb import hgweb
> from mercurial.hgweb import wsgicgi
> application = hgweb("test", "Empty test repository")
> wsgicgi.launch(application)
> HGWEB
$ chmod 755 hgweb.cgi
try hgweb request
$ . "$TESTDIR/cgienv"
$ QUERY_STRING="cmd=changegroup&roots=0000000000000000000000000000000000000000"; export QUERY_STRING
$ python hgweb.cgi >page1 2>&1
$ python "$TESTDIR/md5sum.py" page1
1f424bb22ec05c3c6bc866b6e67efe43 page1