rebase: fix some weird mixed-case naming

rebase: move duplicatecopies next to merge This is preparation for removing open-coded rebase/graft operations. As a side-effect, this exposes proper renames in the working copy when there are conflicts, which shows up in test-shelve.t.

histedit: use merge.graft

graft: use merge.graft

merge: add merge.graft helper This will help unify all the open-coded graft/rebase operations.

duplicatecopies: move from cmdutil to copies This is in preparation for moving its primary caller into merge.py, which would be a layering violation in the current location.

histedit: fix indent The duplicatecopies call should be part of the rebase block.

graft: move rebase cleanup code next to actual rebase This is prep for refactoring the rebase logic.

shelve: add a bundlerepo method

dirstate: merge falls through to otherparent This lets us more correctly fix the state when we use setparents, as demonstrated in the change in test-graft.t.

dirstate: use 'm' state in otherparent to reduce ambiguity In rebase-like operations where we abandon the second parent, we can correctly fix up the state in setparents.

dirstate: properly clean-up some more merge state on setparents