brew.sh: Update `gnu-sed` option

Closes #454.
.osx: Disable Spotlight suggestions from Safari

Safari has a “Spotlight Suggestions” setting that, if left enabled, will send a copy of all search queries to Apple.

Closes #455.
.osx: Add Yosemite’s search results for Spotlight

Yosemite introduces new Spotlight search results, and if you don’t add it to `defaults write com.apple.spotlight orderedItems` it will be removed from the System Preferences → Spotlight → Search Results` list with no way to re-enable them through the System Preferences panel.

Closes #456.
Add .gdbinit
.osx: Fix comment for menu bar items

Closes #459.
Merge commit '411e9dc0eeee1144e704773a5c1a725defb92695'

* commit '411e9dc0eeee1144e704773a5c1a725defb92695':
  .osx: Fix comment for menu bar items
  Add .gdbinit
  .osx: Add Yosemite’s search results for Spotlight
  .osx: Disable Spotlight suggestions from Safari
  brew.sh: Update `gnu-sed` option