The remaining filters should be ported to the structured filter system (i.e. they should be instances of something under includes/changes/ChangesList*Filter*.php , probably a new type for most of them).

We might want to define a new base for things that are not filters per se (like limit and number of pages), e.g. ChangesListParameter. TBD.

Goal is to have everything in the same system, and be able to check relevant information (e.g. whether it's sticky, whether it's covered by "saved filters").

This covers everything outside the menu, including "Show last N changes" and "N days", plus namespaces and tags (the latter are in the menu).