Add tmux

- create tmux.conf
- add tmux.conf to list of files to symlink in script
Fix vim git commit message

referenced:
http://stackoverflow.com/questions/14607584/using-vim-for-git-commit-messages-broken-after-updating-janus
Add tmux aliases
Add tmux pane move and resize bindings
Add -v flag to git commit alias
Add tslime settings to vimrc
Add Racket REPL to $PATH
Update README.md format
Update alias `gall` -> `git add -A`
Add alias for git add . & git add -u
Update alias gau & gall to work properly on git 2.0 and up