Fix a bug in the structure of the --json output.

The various "connected" structures were just dumped into the "start"
structure.  This caused problems if there were multiple connections
(i.e. multiple parallel streams), because the "connected" structures
would overwrite themselves.  Instead, make these structures members
of a "connected" array.

This is technically an incompatible API change, but the prior behavior
was unusable.

Discovered and fix suggested by:	@i2aaron