wip: Reworking capabilities.

The pipeline and request handling will live in the vat module(s).
This makes the capability code a lot leaner and easier to understand.
Update schemas due to changed record defs.
rewrite ecapnp_data into a gen_server.

cleaned up data server to keep a single responsibility,
and drop the msg{} record.

eunit tests severely broken at this point.
all property tests pass.
Bring more of the eunit tests up to speed again.

Keep the object{} record around more in get/set routines,
as that's were the schema lives now.