Status lists as dropdowns instead of radios.

Consolidated status handling into new status_list() function and introduced status.types > types callback so plugins can alter or extend the set more easily (N.B. re-tooling existing status codes is not recommended!)

git-svn-id: http://textpattern.googlecode.com/svn/development/4.x@5456 2fea6a4d-a838-0410-917b-93a53c48e9d2
Not in local language

git-svn-id: http://textpattern.googlecode.com/svn/development/4.x@5457 2fea6a4d-a838-0410-917b-93a53c48e9d2