Establishing a presentation connection steps do not handle failures

[markafoltz]

The steps to establish a presentation connection don't define what happens if the attempt to connect fails. We might want to do that so there is a way for reconnect() to return a connection that doesn't reach a connected state.

Also, the non-normative note that begins "If the connection step does not complete" could be more specific about which algorithm(s) can be retried on which connections so the state transitions make sense.

[tidoust]

See discussion at TPAC

PROPOSED RESOLUTION: For #343, move error handling steps from the start algorithm to the establish a connection algorithm, and remove the note in 6.5.1 about retrying connection establishment.