When trying to merge-patch it will fail if the branch you are trying to merge is
already on the local machine.
This will ask if you want to remove it. The branch will be removed locally and
then pulled from the remote to ensure you are not merging any un-pushed local
changes.
When merge patching it will now detect if there is an unresolved conflict in
your current branch and exit without doing anything.
This is useful when merging multiple branches at once, if you hit a conflict
half way though it would remove the "MERGE_PATCH" file and lose where you where
in the patch
Now the script will exit and not lose the position so you can `--continue`
correctly after fixing the conflicts
