Link to a style guide which has concrete coffeescript style advice
Remove the callback parameter of removeTab()

callback parameter is never passed to removeTab(), so adding it to
the selectionChangeHandlers list causes 'Can not call method call() of undefined'
error after closing the tab.
Merge pull request #830 from sainaen/removeTab_callback_fix

removeTab() shouldn't add callback to selectionChangedHandlers if it's undefined