0.3.6

Upgrading from 0.3.5: There are no backward incompatible changes.

This release includes a significant internal refactoring, designed to better encapsulate responsibility, see #19.

Specifically:

• make Conn public
• move transport responsibilities into Conn from Reader/Writer
• supply callbacks for hooking into Conn events

As part of the refactoring, a few additional clean exit related issues were resolved:

• wait group now includes all exit related goroutines
• ensure that readLoop exits before exiting cleanup
• always check messagesInFlight at readLoop exit
• close underlying connection last