Add error code for use of Basic auth without tls
Added cocoa namespace
Add error message for situation where authUrl call returns error
Merged in jjwchoy/ably-common (pull request #1)

Added cocoa namespace
Merge branch 'master' of bitbucket.org:ably/ably-common
Add blocking-related codes
Updates to WWebhookEnvelope and TError
Add connection params error