Place diff in commit message hints for version bumps

dotfiles/gittum/main.gitconfig

   cmt = !sh -c \
         'git commit --edit --message=\"$(~/.gittum/bin/findcat msg_typo)\"'
   cmv = !sh -c \
-        'git commit --edit --message=\"$(~/.gittum/bin/findcat msg_bumpv)\"'
+        'git commit --verbose --edit --message=\"$(~/.gittum/bin/findcat msg_bumpv)\"'
   cmw = !sh -c \
         'git commit --edit --message=\"$(~/.gittum/bin/findcat msg_wip)\"'
   co = checkout