fixes #630 IPC start elimination fixes #615 IPC close on Windows leaves handle open
fixes #630 IPC start elimination
fixes #615 IPC close on Windows leaves handle open

This reintroduces the code to eradicate the separate transport
start function for IPC, as a incremental step towards the full
fix for 599 and 208.  It also addresses 615, by including revised
logic for the handling of close.

nanomsg/nng,nanomsg/nng,nanomsg/nng,nanomsg/nng