[PATCH] interactive merge in cg-Xmergefile for cogito-0.12.1

I use the attached patch here and its helped me quite a bit.  Thought
I'd send it out for others to use as well.  Prior to 0.12 I could do
this in my own scripts after a cg-merge exited with conflicts.  Resently
it seems 'git-ls-files --unmerged' will no longer list any files that
had conflicts during the merge.

So, this patch modifies cg-Xmergefile to interactively prompt you with
what to do in the event of a merge conflict.  It is set up to work
reasonably well with kdiff3 as is.

If it or a variant gets sucked into cogito -- great.  If there is
already a way to kick off a merge conflict resolution program while
cg-merge is running, please let me know.

Thanks,
James