license, and copyright. This can be used to create custom RecentChanges.
* meta: To support the pagespec functions, metadata about pages has to be
retained as pagestate.
* Fix encoding bug when pagestate values contained spaces.
I kept it to a simple global configuration, rather than using the
preprocessor directive for recentchanges, because that had chicken and egg
problems and seemed overcomplicated. This should work reasonably well,
though it would be good to add some more metadata so that more customised
recentchanges pages can be made.