* code cleanup in lib/exe/css.php
* renamed 'default' userstyle to 'screen' in config_cascade
* splitted core lib/styles/style.css up into all.css, print.css and screen.css

Attention: $lang['register'] has been renamed to $lang['btn_register'],
anyone using that in any plugin or template should adjust it.

Passed every png file through http://www.smushit.com/ysmush.it/ saving some 1-2kb of binary image data

Icon downloaded from http://forum.skype.com/style_emoticons/skype/skype.png

I asked someone internally for file copyright and answer was ok (do
whatever you want)

Previously the rmdir could be executed when the lock directory had been
deleted by another indexer already. This could lead to a race condition
when another indexer call creates the lock again between the if and the
rmdir. This issue still exists for stale lock directories but they
normally shouldn't exist.
This also prevents the loop from becoming an endless loop when the lock
directory can't be created.
This change also fixes a syntax error in the indexer and prevents an
endless loop when the lock directory exists but can't be deleted.

Changes:
  * XML-RPC now correctly allows leading and trailing _
  * Error messages from XML-RPC are correct
  * MEDIA_UPLOAD_FINISH has a sixth param specifying the move function
  * Not having upload rights when using media_upload throws a msg

This patch makes the plugin manager not descend into symbolically linked
directories as this behaviour is not expected from a recursive delete.

Functionality changes:
  * deleteAttachment now triggers MEDIA_DELETE_FILE (closes FS#1568)
  * deletion success msg in mediamanager is correct, even when the ns dir
    was deleted
  * media_delete changed quite a bit

I also adjusted the coding style to match our other JS classes

When a <select> tag has the class "quickselect", this script will
automatically submit its parent form when the select value changes.
It also hides the submit button of the form.