chg: [git-irebase] improving report when conflict arises
chg: [git-irebase] improving report when conflict arises

- adds list of conflicting files.
- use shortstats for the full commit logs (displays only one line with totals)
- keep file-by-file details only for conflicting files.
- display final merge diff if it's less than 50 lines long
- adds the conflicting files filter to the final commands to get more informations.

0k/git-irebase