Add basic version of 'git slurp'

dotfiles/gittum/bin/slurp

+#!/bin/bash
+
+#
+# Slurp - add everything, slurp into a WIP commit and push
+#
+
+test -f .git-slurp-ok || {
+    echo "you don't want this." >&2
+    exit 2
+}
+
+git add .
+git commit -m "WIP slurp $(date -Isec)"
+git push

dotfiles/gittum/main.gitconfig

   rbi = rebase --interactive
   rmv = remote --verbose
   sibling = ! ~/.gittum/bin/sibling
+  slurp = ! ~/.gittum/bin/slurp
   st = status
   sh = show
   who = ! ~/.gittum/bin/who