Xcode duplicate line binding.

xcode_duplicate_instructions.txt

1. Open plist: `open /Applications/Xcode.app/Contents/Frameworks/IDEKit.framework/Versions/A/Resources/IDETextKeyBindingSet.plist`
3. Add the text of 'xcode_duplicate_key.txt' to this file
4. Go to Xcode preferences -> Key Bindings -> Text tab -> Scroll till you see Duplication
5. Click on Duplicate Current Line, add a shortcut for it, eg. Cmnd+D (resolve any duplicate bindings)
6. Open Xcode

xcode_duplicate_key.txt

<key>Duplication</key>
<dict>
	<key>Duplicate Current Line</key>
	<string>moveToBeginningOfLine:, deleteToEndOfLine:, yank:, insertNewline:, moveToBeginningOfLine:, yank:</string>
	<key>Duplicate Lines</key>
	<string>selectLine:, copy:, moveToEndOfLine:, insertNewline:, paste:, deleteBackward:</string>
	<key>Delete Line</key>
	<string>selectLine:, deleteBackward:</string>
</dict>