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

The mail() function shouldn't be executed when no recipients are given.

Empty to, cc or bcc fields could lead to an Internal Server Error:
malformed header from script. Bad header=No recipient addresses found...

This ignores warnings because of the (intentionally) missing url
parameter for the constructor of SimplePie_File.

  * Move file to qsearch.js
  * Rename object to dw_qsearch
  * Remove unnecessary usage of Delay
  * Use $ prefix for jQuery objects
  * Fix result list hiding on click
  * Fix namespace shorting