[userChromeJS] Resize tabs to fill the tab bar immediately after closing a tab (Firefox 4 feature).
This is a script for userChromeJS that fixes Bug 667607 – Make the resizing of tabs configurable caused by fixing Bug 465086 - When closing a tab, other tabs should not resize until cursor leaves toolbar region in Firefox 5 (*not a Greasemonkey script).
When closing tabs other than the rightmost one, the default behavior is to resize each tab "when the mouse is off the tab bar", but change the behavior to resize at the same time the tab is closed.