mq: don't allow patches with some reserved names
The current list of reserved names includes only mq control files.
Also, reserve names starting with ".hg" (to avoid troubles with
e.g. .hgignore and .hgtags), and with ".mq" (to allow future
extensions).
This should fix
issue841.
adding dir/bar
adding foo
dir/bar
foo
adding dir/bar_2
adding foo_2
dir/bar_2
foo_2
adding a
adding c
adding b
adding d
removing a
removing c
recording removal of a as rename to b (100% similar)