Fix SUBSCRIBE expiration change
Fix in-subscription SUBSCRIBE
New tests
Events and UAS refactorization
Fix generating Event for response for request without Event
Fix bug in nksip_subscription
Do not even try to call dialog module if no to tag
Do not allow methods without to tag early
Allow NOTIFY to create dialog
Fix event dialog messages
Best dialog status responses
Automatic Subscription-State in NOTIFY for expired dialogs
Prepare next tests
Full event support!!

* Includes RFC4460/6665 and 5057 (except for GRUU support)
* Full test coverage
Updated response codes
Merge branch 'master' of https://github.com/kalta/nksip_priv
Merge branch 'refs/heads/events'
MESSAGE support

Test included in uac_test.erl
Dialyzer updates
Doc updates