Allow Ctrl- and Shift-clicking links in event handlers

I just recently updated a bunch of my click handlers to not act when the Ctrl or Shift keys are pressed during the click, so that links can be opened in new tabs or windows by the user if so wanted:


// Don't do anything and defer to the default action if a modifier key
// was pressed during the click (to open the link in a new tab, window,
// etc.) - note that this is a truthy check rather than a strict check
// for the existence of and boolean true value of the various event
// properties:
// *
// *
// *
if (event.ctrlKey || event.shiftKey) {