* Removed redundant checks for same env var in ReadEnvironment, extracted Unix domain socket logic to function, and made use of this logic in SetAddress. Adjusted unit tests to verify proper Unix domain socket handling.
* Adding case to revert from Unix domain socket dial function back to TCP
* Adding changelog file
* Only adjust DialContext if RoundTripper is an http.Transport
* Switching from read lock to normal lock
* only reset transport DialContext when setting different address type
* made ParseAddress a method on Config
* Adding additional tests to cover transitions to/from TCP to Unix
* Moved Config type method ParseAddress closer to type's other methods.
* make release note more end-user focused
* adopt review feedback to add comment about holding a lock
Marc Boudreau