Doxygen documentation update:
* Changed alls @addtogroup to @ingroup. @addtogroup adds the comment to the group description, but doesn't add the file, class, function, ... to the group like @ingroup does. See for example http://svn.wikimedia.org/doc/group__SpecialPage.html where it's impossible to see related files, classes, ... that should belong to that group.
* Added @file to file description, it seems that it should be explicitely decalred for file descriptions, otherwise doxygen will think that the comment document the first class, variabled, function, ... that is in that file.
* Removed some empty comments
* Removed some ?>
Added following groups:
* ExternalStorage
* JobQueue
* MaintenanceLanguage
One more thing: there are still a lot of warnings when generating the doc.
* Fix some scripts that assumed include_path was set with various additional directories
Stuff now seems to mostly work when not overriding include_path.
Taking that out of LocalSettings is the next step... whee!
* Removing unused local vars.
* Removing unused global declarations.
* removing one or two pass-by-refs parameter declarations where not required by PHP5.
* Adding some local variable declarations / initializations (initialized to either to array(), null) to keep static code analyzer happy.
* Changing lines like this: "extract( $dbw->tableNames( 'page', 'archive' ) );" to be like this: "list ($page, $archive) = $dbw->tableNamesN( 'page', 'archive' );".
* Add one or two braces to if-else blocks.
