Big cleanup of server/Web-UI code.

* [APP_UI,WEB_UI,SC] Integrated both modules, latter removed.
* [AUTHORIZATION,SC] Removed module, unused.
* [HTML_PL_ERROR,EXT] Added natural language alternative for many error terms.
* [SERVER_EXT,SC] Removed dispatch/1, dispatch_method/4, http_method/2, server_rebase/1.
* [SWOTE,SC] Removed module, unused.
* [WEB_ERROR,SC] Removed module, integrated into HTML_PL_ERROR.
* [WEB_LOGIN,SC] Removed module, unused.
* [WEB_MESSAGE,SC] Removed predicate that stil use DOM-based HTML generation (we now use SCG-based).
* [WEB_SETTINGS,SC] Removed module, unused.
* [WEB_USERS,SC] Removed module, unused.
merge