Update to latest HockeySDK code

- Update HockeySDK
- Adjust implemented HockeySDK protocol
add authenticator demo

* app is now authenticated (email only)
* add buttons to trigger validation / authentication
!! don't merge !! add identifiers for warmup app
update HockeySDK & adapt to interface changes

 Submodule changes to be committed:

 * Vendor/HockeySDK 439c32d...0e1b435 (10):
   > fix button's disabled after failed login
   > refactoring: move auth-logic to the authenticator
   > fix authenticator tests - initialize _NOT_ being in the appstore
   > move email-validation to a common place
   > disable authenticator when running the appStore version
   > cleanup Authenticator interface
   > make installationIdentification KVO'able
   > factor out BITHockeyAppClient to provide network services
   > update documentation on Authenticator
   > Merge branch 'develop' into feature/#19-verifyBetaUsers
add sample for web-based auth/validation
update HockeySDK and adapt to new API
Update to HockeySDK 3.5.0b1
Remove old UDID delegate
Update project
Merge branch 'refs/heads/feature/HockeySDK-#19-verifyBetaUsers' into develop