graphlog: fix --removed "hg log --removed FILE" does not return changesets where FILE was removed, but ones where FILE was changed and possibly removed. The flag is really here to disable walkchangerevs() fast path, which cannot see file removals by scanning filelogs.

test-glog: rewrite more tests using testlog() function

match: consider filesets as "anypats" Matt suggested this on IRC, I do not think the choice is obvious, but this one makes things simpler because while filesets are turned into a list of files into the match objects, it would more be difficult to tell invalid files passed in pats from those expanded from filesets.