tests/test-1102.t

debugindex etc.: add --changelog and --manifest options

These open the changelog and manifest, respectively, directly so you don't
need to specify the path.

The options have been added to debugindex, debugdata and debugrevlog.

The patch also fixes some minor usage-related bugs.

  $ rm -rf a
  $ hg init a
  $ cd a
  $ echo a > a
  $ hg ci -Am0
  adding a
  $ hg tag t1 # 1
  $ hg tag --remove t1 # 2

  $ hg co 1
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg tag -f -r0 t1
  $ hg tags
  tip                                3:a49829c4fc11
  t1                                 0:f7b1eb17ad24