After spending a truely obnoxious amount of time fighting capnp and
libkj, we made the decision to switch to another RPC system. We're no
longer modeling and serializing message types in Capnp and we don't need
the performance which capnp/libkj RPC promises, so there's really no
need for the additional complexity. A slower system which is thread safe
should work fine.

This commit breaks the build in a pretty horrible way and is not
intended to be merged on its own. It simply breaks up the diff.

MUCH simpler