Fix "CFNetwork internal error" messages.
Trigger dispatch on reachability updates
Get rid of accessor with side effects
Add basic metadata to response headers temporarily.

To ease the transition to using the new delegate for metadata, we'll
continue reporting version, stream id, and latency in the response
headers. This maintains parity with the old behavior. This change
should be removed once all the issues have been worked through for
the delegate and its interface locks down.
Merge pull request #68 from kgoodier/delegate-warning-fix

Fix "CFNetwork internal error" messages.
Merge pull request #69 from kgoodier/delegate-metadata-headers

Add basic metadata to response headers temporarily.
Fixed incorrect return value for _encodeHeaders:error:

Fixed _encodeHeaders:error: can return YES (success) on failure when the out error provided is nil
Merge pull request #70 from NSProgrammer/develop

Fixed incorrect return value for _encodeHeaders:error: