* De-servicify router (mostly)
Still uses the redraw service, but it no longer has an intermediate
service of its own.
Also, did a *lot* of test deduplication in this. About 30-40% of the
router service tests were already tested on the main router API instance
itself.
Bundle size decreased from 9560 to 9548 bytes min+gzip.
* Merge `m.mount` + `m.redraw`, update router
Simplifies the router and redraw mechanism, and makes it much easier to
keep predictable.
Bundle size down to 9433 bytes min+gzip, docs updated accordingly.
* Make `mithril/render` just return the `m.render` function directly.
* Deservicify `m.render`, revise `m.route`
- You now have to use `mithril/render/render` directly if you want an
implicit redraw function. (This will likely be going away in v3.)
- Revise `m.route` to only `key` components
* Add `redraw` to `m.render`, deservicify requests
* Test error logging
* Update docs + changelog [skip ci]
- Remove docs for it
- Remove tests for it
- Add runtime check for unexpected reassignment, since we can't freeze
the property (we internally have to be able to modify it)
