abort: added support for merge...
abort: added support for merge
This adds support of `hg merge --abort` to `hg abort` plan.
This involves refactoring `hg.merge` into two different
functions removing the abort logic of `merge` from `hg.merge`
and then creating a seperate `hg.abortmerge` to handle the
abort logic so that the abortion of merge can be called
independently.
`hg.abortmerge` is then registered as `abortfunc` for the
state detection API so that `commands.abort` can use it to
deal with an unfinished merge operation.
Results are shown as tests.
Differential Revision:
https://phab.mercurial-scm.org/D6588
