copies: split u1/u2 to u1u/u2u and u1r/u2r These will be made different in case of grafts by another patch in this series.

copies: style fixes and add comment

copies: limit is an optimization, and doesn't provide guarantees

revset: do not rewrite ':y' to '0:y' (issue5385) That's no longer valid since the revision 0 may be hidden. Bypass validating the existence of '0' and filter it by spanset.

revset: extract function that creates range set from computed revisions So we can pass m=0 to _makerangeset() even if the revision 0 is hidden. Hidden revisions are filtered by spanset.

lazymanifest: write a more efficient, pypy friendly version of lazymanifest

hg: set default path correctly when doing a clone+share (issue5378) Before, if performing a clone+share from a repo that was itself using shared storage, the share code would copy paths.default from the underlying repo being shared, not from the source given by the user. This patch teaches hg.clonewithshare to resolve paths.default and pass it to share so it can be written to the hgrc accordingly.