Enhance the file filtering capabilities.
We now allow filtering through either pipes or pairs of temporary
files. The latter appear to be mandatory for use on Windows.
adding foo
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 1 changesets, 1 total revisions
pulling from ../branch
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
(run 'hg update' to get a working copy)
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 2 changesets, 2 total revisions
foo
bar
6f4310b00b9a147241b071a60c28a650827fb03d 644 foo