TYPO3 Core

Problem:
There's no possibility to hide versioning and workspaces.
The possibility to remove all versioning/ws related buttons and menu entries from the TYPO3 backend would result in a more cleaner (and also more logical) GUI. There would be no need anymore to explain a customer that the workspace selector has no function in his installation.
Besides this, versioning/ws needs a serious amount of performance also when it is not used. There are many sql queries done to find out, whether there are versions of a record or to find out whether a page is in a versionized branch.

Solution:
Give admins the possibility the un-install the extension 'version'. This is done by moving it from $TYPO3_CONF_VARS['EXT']['requiredExt '] to $TYPO3_CONF_VARS['EXT']['extList'] but that raises some other problems.
Having 'version' in extList will do fine for new installations but the more common case is updating an existing installation (with an existing 'extList' in localconf.php) to TYPO3 4.3. Then the changed extList from config_default.php will be ignored, resulting in versioning/ws being disabled after update. Solution for this: add a function to the update wizard in install tool which explains the new situation and allows to install 'version'.
The TCA description of table sys_workspace is currently written to t3lib/stddb and therefore always loaded. To make table 'sys_workspace' only visible when extension 'version' is loaded move its TCA description to sysext/version/.

And finally add conditions to check if 'version' is loaded to all versioning/ws related methods to prevent them doing unneeded sql-queries and other expensive stuff.

related discussion:
http://lists.typo3.org/pipermail/typo3-project-4-3/2009-August/001807.html
(issue imported from #M11828)