.osx: Suppress error messages when running `~/.osx` twice

Closes #266.
webstorm settings update
monokai iterm
pref
Merge branch 'master' of https://github.com/singuerinc/dotfiles

# By Mathias Bynens (11) and others
# Via Nahuel Scotti (1) and singuerinc (1)
* 'master' of https://github.com/singuerinc/dotfiles:
  Update .osx
  update
  pref
  .osx: Stop iTunes from responding to the keyboard media keys
  .osx: Disable automatic spell checking in Mail.app
  .osx: Disable inline attachments in Mail
  .osx: Make coding style more consistent
  .osx: Remove old iTunes commands
  .osx: Add threaded email display settings for Mail.app
  .brew: Move casks to their own file
  .osx: Disable continuous spell checking in Messages.app
  .osx: Disable smart quotes in Messages.app
  .functions: Add `tre` shorthand
  .osx: Consistently specify the type for `dict-add` actions
  .osx: Use plain text smileys in Messages
  .osx: Remove “Enable access for assistive devices”
  Add `np` function to ease publishing node modules
  update

Conflicts:
	.slate
	.zshrc
Merge branch 'master' of https://github.com/mathiasbynens/dotfiles

# By Mathias Bynens
# Via Mathias Bynens
* 'master' of https://github.com/mathiasbynens/dotfiles:
  .osx: Suppress error messages when running `~/.osx` twice

Conflicts:
	.osx