tests/test-issue842.t

tests: add filtercr.py helper for progress tests

The two tests that used filtercr.py already used a slightly different
version, which explains why test-convert-svn-move.t changed after
switching to using $TESTDIR/filtercr.py.

http://mercurial.selenic.com/bts/issue842

  $ hg init
  $ echo foo > a
  $ hg ci -Ama
  adding a

  $ hg up -r0000
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved

  $ echo bar > a

Should issue new head warning:

  $ hg ci -Amb
  adding a
  created new head

  $ hg up -r0000
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved

  $ echo stuffy > a

Should not issue new head warning:

  $ hg ci -q -Amc

  $ hg up -r0000
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved

  $ echo crap > a
  $ hg branch testing
  marked working directory as branch testing

Should not issue warning:

  $ hg ci -q -Amd