tests/test-extra-filelog-entry.t

test-revert: add methodical revert with explicit file path

We now also test reverting file to the working directory parent
content. However this differs from the previously introduced test by using
the explicit path of each "case file" when calling revert. This should
result in the same result regarding file content and backup creation,
but the output of the `hg revert` call should differ.

Issue351: mq: qrefresh can create extra revlog entry

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "mq=" >> $HGRCPATH

  $ hg init
  $ hg qinit

  $ echo b > b
  $ hg ci -A -m foo
  adding b

  $ echo cc > b
  $ hg qnew -f foo.diff
  $ echo b > b
  $ hg qrefresh

  $ hg debugindex b
     rev    offset  length  ..... linkrev nodeid       p1           p2 (re)
       0         0       3  .....       0 1e88685f5dde 000000000000 000000000000 (re)