Git: add rbimbm alias

* Add shortcut for $(git rebase -i $(git merge-base master head))
* Easily modify (e.g. squash, edit) commits in the current branch
Vim: turn off paste mode by default
Vim: improve ctrlp match window results

Match window defaults:
* min:1 (height)
* max:10 (height)
* results:<synced to max>

That leaves matches limited to 10 by default, leaving out good matches.
Increase match window results to overcome default limitation.