* Added ApiQueryBase::addJoin() which provides a cleaner interface to construct JOIN queries. Behind the scenes this still uses the old, ugly way, but it'll be easy to rewrite when/if the Database class gets its own function for JOINs
* Used addJoin() in query modules where necessary
* Removed FORCE INDEX (rc_timestamp) from ApiQueryRecentchanges: it's nigh impossible to integrate with addJoin() and it doesn't seem to be necessary anyway (my MySQL instance automatically chooses rc_timestamp)
* Add @addtogroup tags to various classes, to try and group conceptually-related classes together.
* Add brief descriptions to various Special pages, thanks to Phil Boswell.
* Moving some docs to be right above the classes they represent, so that they are picked up.
* Convert "$dbw =& wfGetDB( DB_MASTER );" --> "$dbw = wfGetDB( DB_MASTER );"
* convert "$skin =& $wgUser->getSkin();" --> "$skin = $wgUser->getSkin();"
For the time being have not changed the function definitions of wfGetDB() or User::getSkin() [i.e. they are still both return-by-ref], so as to ensure the interface does not change for extensions [some of which may still be trying to run on PHP4 environments]. However presumably at some point this can be changed too.
Also includes tiny tweak to newlines in parserTests - will show 1 rather than 2 newlines between the "Reading tests from" strings when in quiet mode.
* removing some unused global declarations.
* removing or commenting out or adding comments for unused local vars.
* Adding one or two local var declarations.
* Declaring $matches array passed to preg_match() / preg_match_all() as array() before using [not required, just have a slight preference for the explicitness].
* remove one or two pass-by-reference function declarations where the value is not modified.
* Adding some braces to if-else blocks.
* In Parser.php, stripstrate is now an object rather than an array as per r17820, so we no longer need ask for a reference to it (as in "$x =& $this->mStripState;"), and in fact it's probably just simpler to get rid of $x altogether.
* Moving some preg regexes from "" quoting to '' quoting to stop static analyzer whinging about bad escape sequences.
... up to "LinksUpdate.php" in the includes/ directory.
