.aliases: Add `jsc` alias

Useful for testing code in JavaScriptCore.

Hat tip: https://twitter.com/RussB/status/420409644117262336 (via @rauschma)
.functions: Make `np` remove `node_modules`

This lets you catch cases where you forgot to add a dependency to `package.json`.

Closes #321.
.osx: Support multiple `systemuiserver` pref files

Closes #319.
Brewfile: Install `p7zip` (i.e. `7z` etc.)
.osx: Kill `cfprefsd` after changing preferences

As of OS X 10.9 this is necessary to make sure the changes persist.

Closes #330.
Merge branch 'master' of github.com:mathiasbynens/dotfiles

# By Mathias Bynens (3) and others
# Via Mathias Bynens
* 'master' of github.com:mathiasbynens/dotfiles:
  .osx: Kill `cfprefsd` after changing preferences
  Brewfile: Install `p7zip` (i.e. `7z` etc.)
  .osx: Support multiple `systemuiserver` pref files
  .functions: Make `np` remove `node_modules`
  .aliases: Add `jsc` alias

Conflicts:
	.osx
	Brewfile