Todo for xml interface 'ConTeXtXML' extension:
- fix ‘outdated revision’ after external xml file update
- add <cd:iref/> to mtx-wikipage processing
- decide on allowed commands/tags and test on those when saving
- (maybe) add a dedicated editing page with split fields
- document the new stuff (ref pages, env/cmd split, variants)
- fix/extend the {{cmd}} template
- move existing pages to a safe location
- existing page merging (jikes!)
- prepare code for merging to/from updated xml doc files
- combine the current 'context' extension with the new 'ConTeXtXML' extension
- add a template to crossreference other parameters /arguments from within doc pages