match: move matchers from sparse into core
The sparse extension contains some matcher types that are
generic and can exist in core.
As part of the move, the classes now inherit from basematcher.
always(), files(), and isexact() have been dropped because
they match the default implementations in basematcher.
$ rm -rf a
$ hg init a
$ cd a
$ echo a > a
$ hg ci -Am0
adding a
$ hg tag t1 # 1
$ hg tag --remove t1 # 2
$ hg co 1
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg tag -f -r0 t1
$ hg tags
tip 3:a49829c4fc11
t1 0:f7b1eb17ad24
$ cd ..