.aliases: Add `lscleanup` alias that cleans up LaunchServices

This removes duplicates in the “Open With” menu.
.osx: Enable HiDPI display modes without using Quartz Debug
.aliases: Add `ios` alias to launch iOS Simulator
.functions: Add `unquarantine` which force-removes a downloaded app or file from the quarantine

Thanks to @jasomill on Hacker News: http://news.ycombinator.com/item?id=4307379.
.brew: Fix typo

Thanks to @oschrenk for the heads up on https://github.com/mathiasbynens/dotfiles/commit/8a79072feb638ab964f4ba6385551be4e7ae3edf#commitcomment-164452.
.osx: Use a modified version of the Pro theme in Terminal.app
.osx: Allow hitting the Backspace key to go to the previous page in Safari’s history
.brew: Remove outdated versions from the cellar
.osx: Don’t group windows by application in Mission Control

This makes it use the old Exposé behavior instead.
.aliases: Add `mergepdf` alias that concatenates PDF files

Credit goes to Fritz Stelluto: http://blog.gotofritz.net/howto/joining-pdf-files-in-os-x-from-the-command-line/.
.functions: Add `note` and `remind`

`note` quickly adds a note to Notes.app, and `remind` adds a reminder to — you guessed it — Reminders.app. Both applications are available on OS X 10.8.

Note that in order for `note` to work, iCloud sync must be enabled for Notes.app.
.osx: Explain how to use the ⌘ + F iTunes hack with other system languages

Thanks to @renaudleo for this discovery.
.aliases: Make `fs` work with both GNU `stat` and OS X `stat`
.osx: Add the keyboard shortcut ⌘ + Enter to send an email in Mail.app
.osx: Reveal IP address, hostname, OS version, etc. when clicking the clock in the login window
.osx: Ask for the administrator password upfront

Use @cowboy’s `sudo` keep-alive snippet (https://gist.github.com/3118588)
to continuously update the existing `sudo` time stamp until `.osx` has
finished running.
.osx: Kill the affected applications by their new OS X 10.8 names as well

E.g. by killing both iCal and Calendar we support pre-OS X 10.8 and OS X 10.8 itself.
.osx: Add a note about the iTunes track notifications in OS X 10.8
.functions: Rename `md` to `mkd` now that OS X 10.8 has an utility named `md`
.osx: Remove the iTunes track notifications tweak

It crashes the Dock in OS X 10.7.4 and doesn’t work in OS X 10.8 anyway.

Ref. https://github.com/mathiasbynens/dotfiles/commit/45c1bced7371b93a49f884bc6fe868571fe94402#commitcomment-1671603.