Fix cumbersome pasting with Cmd + V

[parisk]

For some reason, setting the element's contentEditable value to true within a keyboard event, while the element has focus, did not allow pasting with clipboard, unless the element gets clicked explicitly.

[Tyriar]

This might be a browser security feature, ensuring that a user action is performed before accessing the clipboard.

[parisk]

I do not think so. The thing is that when you press Cmd + V on OS X Chrome (which is a user action), it does not fire the paste event. This happens only when the textarea's contenteditable value is being set to true from false and no click has happened before the keyboard event.