Core

Problem:
TYPO3 Backend loads first the styles for v3.x and afterwards t3skin, which overwrites the previously made definitions by the core. This su**s.

• Remove all (not absolutely needed) CSS from core
• Add the now missing CSS to t3skin
• Restructure the CSS files and separate between structure definitions (height, width, position, etc.) and visual styles (color, border, …)

Please apply it with --binary option for the patch command, as images are included. Please also use --force, as deleting some files fails (I think because of different $Id$ strings). Also attached files-to-delete.txt for the core-dev who committs this patch and want's to delete the unused 0-byte files.

Find some ideas and explanations of how-to-use in the "Backend Skinning Guide" doc_core_skinning [1]

The backend without an installed skin is still usable to install a skin - that was our goal and not more

#21900: Add API to add stylesheet directories
added $TBE_STYLES['stylesheetDirectories'], which is reverted by this patch.
Instead we use $TBE_STYLES['skins'] to include additional stylesheet directories

#21900: Backend not printable if more than one page
added $TBE_STYLES['styleSheetFile_print'], which is reverted by this patch.
Instead the file is included like all the other files, but definitions placed inside @media print { .. }

#21900: Add Viewport layout to BE
introduced a second <div id="typo3-toolbar">. This patch silently renames this to typo3-topbar (which then contains the toolbar); this has been agreed with Stefan

This patch adds lots of CSS files, which have to be loaded by your browser. We have to find a solution for beta3, to concatenate (compress) them. This also leads to an unstyled backend in IE6 as it seems not to accept more than 31 CSS files [2].

This was task of T3UXW09 Team 3, major credits go to Fabien Udriot.
(issue imported from #M14195)