clone: rename "rev" to "revs" since there can be many It was a little tricky in hg.clone(), since there was a local "revs" variable defined there, but "rev" was never used after "revs", so I just overwrote it. Note that clonewithshare() should also have its "rev" argument renamed to "revs", but I'll leave that to someone else. Differential Revision: https://phab.mercurial-scm.org/D3016