.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.
.osx: Use `-array` instead of `-array ""`

Ref. #350.
.osx: Remove “increase window resize speed”

Sadly, this doesn’t work anymore in OS X 10.10.
README: Tweak `~/.path` example