dirstate: remove the python-side whitelist of allowed matchers
This whitelist is too permissive because it allows matchers that contain
disallowed ones deep inside, for example through `intersectionmatcher`.
It is also too restrictive because it doesn't pass through
some of the matchers we support, such as `patternmatcher`.
It's also unnecessary because unsupported matchers raise
`FallbackError` and we fall back anyway.
Making this change makes more of the tests use rust code path,
and therefore subtly change behavior. For example, rust status
in largefiles repos seems to have strange behavior.
Issue351: mq: qrefresh can create extra revlog entry
$ echo "[extensions]" >> $HGRCPATH
$ echo "mq=" >> $HGRCPATH
$ hg init repo
$ cd repo
$ hg qinit
$ echo b > b
$ hg ci -A -m foo
adding b
$ echo cc > b
$ hg qnew -f foo.diff
$ echo b > b
$ hg qrefresh
$ hg debugindex b
rev linkrev nodeid p1-nodeid p2-nodeid
0 0 1e88685f5dde 000000000000 000000000000