Add Shift+Tab map for tab complete in insert mode

Feature parity with `<c-p>` `<c-n>` tab completion duo.
Set Vim's colorcolumn to 80 characters

* We have an 80 character formatting limit
* This makes it obvious where that limit is
Adds `vim-ruby` back to `vimrc.bundles`

Removal in https://github.com/thoughtbot/dotfiles/commit/deb7ee5948a0df56c2a68fc2dab22fd31d70a204
was accidental.

Also, removes `vim/bundle` directory as it is no longer useful to us, since
`vundle` creates it when it needs to.
Allow stylesheets to autocomplete hyphenated words
Add /usr/local/bin to PATH before /usr/bin

This is for homebrew binaries to work.

Load `rbenv` after adding `$HOME/.bin` and `/usr/local/bin` to `PATH`, but
before adding project-specific binstubs.
tat command now works in directories with periods

- Running `tat` in the robots.thoughtbot.com directory was throwing a
'bad session name' tmux error
- See http://sourceforge.net/p/tmux/tickets/109/
Set Vim's spellfile to $HOME

Running `zg` adds words to the `spellfile`:

https://github.com/thoughtbot/dotfiles/commit/4f5a2edc336970b8a1c7eded3934182810abeb20
http://robots.thoughtbot.com/vim-spell-checking

Setting the spellfile keeps it out of its default location, `vim/spell`, which
would otherwise be inside thoughtbot/dotfiles. We don't necessarily want to
share the `spellfile` across the team.
Update for Vundle's new interface

* Vundle now lives at gmarik/Vundle.vim

See https://github.com/gmarik/Vundle.vim/blob/master/doc/vundle.txt#L345-L369
Make it easy to checkout GitHub pull requests

This alias makes the following workflow possible:

Look at changes:

    git co-pr 123
    git diff origin/master

Bundle, validate tests are passing:

    bundle
    rake

Rebase interactively, squash, and potentially improve commit messages:

    git rebase -i master

Merge code into master:

    git checkout master
    git merge pr/123 --ff-only

Push:

    git push origin master

Clean up:

    git branch -D pr/123
Allow personal overrides to psqlrc

I wanted to add my own customizations after reading @mike-burns' post on
[`psqlrc`](http://robots.thoughtbot.com/an-explained-psqlrc).

As a result of this change, `.psqlrc` requires that a `.psqlrc.local`
exist in the home folder because `psql` cannot do conditional sourcing
of files in the style that we use in other foundation dotfiles. Touching
the file to ensure it exists (even if blank) prevents `psql` from
exiting with an error if the user does not provide their own custom
configuration.

Additional changes:
* Updating the documentation with regard to which files get excluded.
Improve ag tab completion

* Remove unnecessary `uniq`
* Look for tags in tmp/tags or .git/tags
* Send errors to /dev/null if the file(s) do not exist

See http://tbaggery.com/2011/08/08/effortless-ctags-with-git.html for an
explanation behind the reasoning for .git/tags.
Add vim-multiple-cursors plugin for Vim
Revert "Add vim-multiple-cursors plugin for Vim"

This reverts commit 422a6f6d3324a7c6060793657054025d41a7bab3.

Want to go through a PR cycle.
\unset QUIET is case sensitive
Introduce ~/.zsh/configs

Just before loading `~/.zshrc.local`, load:

1. `~/.zsh/configs/pre/**/*`
2. `~/.zsh/configs/**/*` # excluding pre and post
3. `~/.zsh/configs/post/**/*`

About the zsh glob:

- `.`: only produce normal files.
- `-`: follow symlinks to their final file; skip any broken links.
- `N`: do not complain about zero matches.

Big ups to Pat Brisbin for finding `N`.
Introduces `git_template` for init templating

Inspired by http://tbaggery.com/2011/08/08/effortless-ctags-with-git.html

* Make `ctags` executable configurable
* Adds `git ctags`
* Runs `ctag` on `commit` / `branch` / `checkout`
* Extensible via `~/.git_template.local/hooks/{pre,post}-*`
* explain `git_template` under `git` section
Add vim-repeat plugin

Repeat.vim remaps `.` in a way that plugins can tap into it. With this
plugin you can, for instance, repeat commands from surround.vim.
Moved exports from zshrc to it's own dedicatd file
Added tab completion for golang