[TYPO3-core] RFC: Refactored clickmenu to speed up the BE

[Jeff Segars]

>>   ok. here's my new version for the clickmenu patch!

>  Hm. Regardless of what I do (clear browser cache, restart browser,
> logout/login, restart Apache) I see error in FF when I click on a
> page tree icon:

>  showClickmenu is not defined
>  onclick(click clientX=0, clientY=0)

I'm having the same problem here in FF and Safari.  It appears that
clickmenu.js is never loaded.