Remove public Value protocol methods

There was originally the promise of serializing/deserializing your own
types, but without a way to set up the expectation on both sides of the
exchange this approach was naive. We can revisit this using
Expression<T> in the future, but we need more directly applicable
functions.

Signed-off-by: Stephen Celis <stephen@stephencelis.com>
Perform internal database operations in FIFO queue

This breaks our embargo with Foundation, but our application had been
suffering as a result.

Signed-off-by: Stephen Celis <stephen@stephencelis.com>