'remove a file or directory (or a directory tree if rec=1) with
checkin message msg.'

def remove(self, rec=1, msg='removed    by    py    lib    invocation'):

    if (self.rev is not None):
        raise py.error.EINVAL(self, 'revisions    are    immutable')
    self._svncmdexecauth(('svn    rm    -m    "%s"    "%s"' % (msg, self._escape(self))))
    self._norev_delentry(self.dirpath())
