.functions: Add `calc`
.bash_profile: Move the `LANG` & `LC_ALL` exports into `.exports`
.osx: Remove the iTunes Ping settings

Apple officially closed the iTunes Ping service on September 30th, 2012 (http://i.imgur.com/U7bHo.jpg).
.osx: Document the various values for Hot Corners settings
.osx: Clarify that the iTunes settings are for pre-iTunes 11 only
Merge branch 'master' of https://github.com/mathiasbynens/dotfiles