gitconfig: pull.ff = only
gitconfig: alias.ff = merge --ff-only
gitconfig: push.default = simple (default as of Git 2.0)

Setting this prevents the warning about it being a new default.
gitconfig: fetch.prune = true
gitconfig: use SSH transport for GitHub, not HTTPS etc.
gitignore: globally ignore .DS_Store
tmux: bind + to resize 48 columns to the right.