tests/histedit-helpers.sh

largefiles: handle logging from outside the repo

It's probably possible to refactor so that the 'if m._cwd' check isn't
necessary, but the False case is the typical case (i.e. run from the root of the
repo), and simpler to read.

An exact path to a largefile from outside the repo was previously ignored.

match.rel('.hglf') will handle figuring out both the correct '../' length to the
standin directory if inside the repo, or path/to/repo from outside, at the cost
of a pconvert() to keep the patterns using '/' on Windows.

fixbundle() {
    grep -v 'saving bundle' | grep -v 'saved backup' | \
        grep -v added | grep -v adding | \
        grep -v "unable to find 'e' for patching" | \
        grep -v "e: No such file or directory"
}