New global function added called 'get'
This is because top.document.getElementById is used so often, we
actually save 2kb by having a function to return the object, plus it's
much more readable to have:
get('serverMessage').style.opacity = '1';
rather than
document.getElementById('#serverMessage').style.opacity = '1';
newTab now has a z-index of 0 so that it slides behind other tabs when
new tabs are opened
serverMessage is now display: inline-block and hiding and showing is
done on moving the left position to 0 or 2000px to show or hide (doing
the show/hide on changing the display type was causing reflow issues
which seemed to mean occassionally the newTab wasn't moving to the
correct position)
