* Drop useless and possibly filesorting ORDER BY cl_to from list=categorymembers
* Handle ORDER BY cl_sortkey, cl_from (possibly with DESC appended to each of them) with addWhereRange() calls
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.
* Fixed allcategories paging
* Removed DISTINCT from allcategories query (which only selects a UNIQUE field anyway)
* Improved categorymembers performance; it used to filesort
* Disabled cmstart and cmend for cmsort=sortkey to prevent filesorting
* Fixed categorymembers paging for cmdir=desc
