tests/test-issue612.t

subrepos: abort commit by default if a subrepo is dirty (BC)

This changeset flips the default value of ui.commitsubrepos setting
from True to False and adds a --subrepos flag to commit.

The commit, status, and diff commands behave like this with regard to
recusion and the ui.commitsubrepos setting:

          | recurses      | recurses
          | by default    | with --subrepos
  --------+---------------+----------------
  commit: | commitsubrepo | True
  status: | False         | True
  diff:   | False         | True

By changing the default from True to False, the table becomes
consistent in the two columns:

* without --subrepos on the command line, commit will abort if a
  subrepo is dirty and status/diff wont show changes inside subrepos.

* with --subrepos, all three commands will recurse.

A --subrepos flag on the command line overrides the config settin.g

http://mercurial.selenic.com/bts/issue612

  $ hg init
  $ mkdir src
  $ echo a > src/a.c
  $ hg ci -Ama
  adding src/a.c

  $ hg mv src source
  moving src/a.c to source/a.c

  $ hg ci -Ammove

  $ hg co -C 0
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved

  $ echo new > src/a.c
  $ echo compiled > src/a.o
  $ hg ci -mupdate
  created new head

  $ hg status
  ? src/a.o

  $ hg merge
  merging src/a.c and source/a.c to source/a.c
  1 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ hg status
  M source/a.c
  R src/a.c
  ? source/a.o