Fix bzrlib.builtins.cmd_ls() recursion argument for pre 2.0 bzrlibs.

Fix bzrlib.builtins.cmd_ls() recursion argument for pre 2.0 bzrlibs.

$ python test.py libbe.storage.vcs.bzr
...
======================================================================
ERROR: Children list should be revision dependent.
----------------------------------------------------------------------
Traceback (most recent call last):
  File ".../libbe/storage/base.py", line 997, in test_
get_previous_children
    ret = sorted(self.s.children('parent', revision=revs[i]))
  File ".../libbe/storage/base.py", line 314, in child
ren
    return self._children(*args, **kwargs)
  File ".../libbe/storage/vcs/base.py", line 811, in _
children
    path = self.path(id, revision, relpath=False)
  File ".../libbe/storage/vcs/base.py", line 716, in p
ath
    path = self._vcs_path(id, revision)
  File ".../libbe/storage/vcs/bzr.py", line 145, in _v
cs_path
    self.repo, revision=revision, recursive=True)
  File ".../libbe/storage/vcs/bzr.py", line 163, in _v
cs_listdir
    cmd.run(revision=revision, path=path, recursive=recursive)
  File "/usr/lib/python2.5/site-packages/bzrlib/commands.py", line 800, in ignor
e_pipe
    result = func(*args, **kwargs)
TypeError: run() got an unexpected keyword argument 'recursive'
...

The change is due to (in bzr.dev):

revno: 4206.2.1
revision-id: ian.clatworthy@canonical.com-20090326133831-orvicmmc6w29mpfp
parent: pqm@pqm.ubuntu.com-20090326063330-evutyvml3067dpsz
committer: Ian Clatworthy <ian.clatworthy@canonical.com>
branch nick: bzr.ls-recursive-off
timestamp: Thu 2009-03-26 23:38:31 +1000
message: ls should be non-recursive by default

Which occured between bzr-1.9rc1 and 2.0rc1.:

bzr.dev$ bzr tags
2.0rc1               4634.9.1
...
bzr-1.9rc1           3815.3.1
bzr-2.0.1            4634.73.2
...