Update worksheet
Thread Bindings as implicit

I'm not sure this is a good idea, but it seems safe because it saves
quite some boilerplate and there are never two instances of bindings
around - otherwise we'd get a compile error.
ARGH reduce type errors WIP

Static Caching is still a mess...
Static caching: Propagate renames + mess WIP

Storing the renames decided is probably a good idea.
The rest... not so good.

This commits also adds some TODOs to make this saner.

Time to go (back? at all?) to the whiteboard.
Reenable (conditionally) type consistency checks

This makes things sane again, and adds a new knob to disable
typechecking for debugging.