match: compose 'set:' pattern as matcher
Baby step towards porting fileset to matcher composition.
We can't use the exactmatcher since it would provide a computed set as exact
paths. That's why we use the predicatematcher with fset.__contains__. This
will be cleaned up later.
The test change in test-glog.t means that the "set:copied()" pattern is no
longer be processed as a slow path. That's because the fset is empty. This
will also change in future patches.
$ hg init
$ touch unknown
$ touch a
$ hg add a
$ hg ci -m "1"
$ touch b
$ hg add b
$ hg ci -m "2"
Should show unknown
$ hg status
? unknown
$ hg revert -r 0 --all
removing b
Should show unknown and b removed
$ hg status
R b
? unknown
Should show a and unknown
$ ls
a
unknown