This way we can have a handle of the errors in the high-level
components. Before they were implicitly discarded.

Also, spago build used now.

Not everything compiles yet.

Turns out that magic "?" in the url was added by having a H.button in
the show controls/show sidebar/show tree in the top bar.

Also, fixed styling of "info" dropdown.

This is to trigger reloading of main page.

Error is still shown because of some docView issues.

But controls doesn't and sidebar throws exception...

NOTE: This still doesn't work fully