tiny modification of striplangs.php's help

Making it more aesthetic, and consistent with the others bin/*php scripts

This fixes the hiding of the highlighting of the current section when
the mouse leaves the edit section button.

  * Fix selector in subtree loading callback
  * Remove HTML inconsistencies between AJAX and plain PHP lists
  * Unify icon and CSS class switching in dw_tree and dw_mediamanager

Fix the (media manager) JavaScript by adding a missing parentheses

Make it faster, prettier, less wrong, add UI effects, use jQuery UI Dialog,
Abstract tree view stuff away into jQuery.dw_tree

There are probably more functions that should go in here

The ajax quicksearch sent a request on every keystroke instead of
waiting for the user to stop typing.

Conflicts:
	lib/exe/css.php

  * Increase HTTP cache time since the resources are timestamped on request
    anyway
  * Check userscript.js only once for JS cache validation
  * Use cache class