mq: prepare a strip extension for extraction Strip will lives in its own extension. The extension is surprisingly called `strip`. (as discussed in issue3824) The `mq` extension force the use of the strip extension when its enabled. This will both necessary for backward compatibility (people expect `mq` to comes with strip) and become some utility function used by `mq` will move in the strip extension.

from mercurial import cmdutil

cmdtable = {}
command = cmdutil.command(cmdtable)
testedwith = 'internal'