* The serialized message cache, which would have been redundant, has been removed. Similar performance characteristics can be achieved with $wgLocalisationCacheConf['manualRecache'] = true;
* Added a maintenance script rebuildLocalisationCache.php for offline rebuilding of the localisation cache.
* Extension i18n files can now contain any of the variables which can be set in Messages*.php. It is possible, and recommended, to use this feature instead of the hooks for special page aliases and magic words.
* $wgExtensionAliasesFiles, LanguageGetMagic and LanguageGetSpecialPageAliases are retained for backwards compatibility. $wgMessageCache->addMessages() and related functions have been removed. wfLoadExtensionMessages() is a no-op and can continue to be called for b/c.
* Introduced $wgCacheDirectory as a default location for the various local caches that have accumulated. Suggested $IP/cache as a good place for it in the default LocalSettings.php and created this directory with a deny-all .htaccess.
* Patched Exception.php to avoid using the message cache when an exception is thrown from within LocalisationCache, since this tends to fail horribly.
* Removed Language::getLocalisationArray(), Language::loadLocalisation(), Language::load()
* Fixed FileDependency::__sleep()
* In Cdb.php, fixed newlines in debug messages
In MessageCache::get():
* Replaced calls to $wgContLang capitalisation functions with plain PHP functions, reducing the typical case from 99us to 93us. Message cache keys are already documented as being restricted to ASCII.
* Implemented a more efficient way to filter out bogus language codes, reducing the "foo/en" case from 430us to 101us
* Optimised wfRunHooks() in the typical do-nothing case, from ~30us to ~3us. This reduced MessageCache::get() typical case time from 93us to 38us.
* Removed hook MessageNotInMwNs to save an extra 3us per cache hit. Reimplemented the only user (LocalisationUpdate) using the new hook LocalisationCacheRecache.
Note that case mappings will only be used if mbstring extension is not present.
Normalization data files updated to Unicode 5.1.0; passes the automated tests.
Seem to have long since lost the script I originally used to generate the Utf8Case.php mapping file, which appears not to have been updated since 2002 or so. :)
Made a new one and moved it into the UtfNormal sub-library.
Note a couple limitations:
* Case mapping (still) uses only the 1:1 simple mappings. Any full or locale-specific mappings are ignored.
* These case mappings are not used anyway when the PHP mbstring extension is available; mbstring's case conversion functions are used instead, with whatever version of Unicode support and whatever complex mapping support they may or may not have.
* The generated Utf8Case.php file is not used directly -- you must also regenerate the serialized version in the 'serialized' directory after updating it to a new Unicode version.
* Made lines from initialiseMessages() appear as list items during installation
* Moved the bulk of the localisation data from the Language*.php files to the Messages*.php files. Deleted most of the Languages*.php files.
* Introduced "stub global" framework to provide deferred initialisation of core modules.
* Removed placeholder values for $wgTitle and $wgArticle, these variables will now be null during the initialisation process, until they are set by index.php or another entry point.
* Added DBA cache type, for BDB-style caches.
* Removed custom date format functions, replacing them with a format string in the style of PHP's date(). Used string identifiers instead of integer identifiers, in both the language files and user preferences. Migration should be transparent in most cases.
* Simplified the initialisation API for LoadBalancer objects.
* Removed the broken altencoding feature.
* Moved default user options and toggles from Language to User. Language objects are still able to define default preference overrides and extra user toggles, via a slightly different interface.
* Don't include the date option in the parser cache rendering hash unless $wgUseDynamicDates is enabled.
* Merged LanguageUtf8 with Language. Removed LanguageUtf8.php.
* Removed inclusion of language files from the bottom of Language.php. This is now consistently done from Language::factory().
* Add the name of the executing maintenance script to the debug log. Start the profiler during maintenance scripts.
* Added "serialized" directory, for storing precompiled data in serialized form.