Merge pull request #351 from AlexeyAfanasyev/master

#337 Auth provider should return cancelable protocol
Fix: test testOfflineCachingAttributeInOffline fails when run alone, but succeeded in a context.
RFWebResponse cache managed object was refactored with a main goal to make future cache migrations easier. All object fields except indexed were hidden under transformable property.
iOS 8 test
Behaviour of default json deserializator was changed: in a case of "not found" server answer (JSON is valid, but does not contain any information) was rising error. Now it returns an empty collection.
1. In search view now it's not possible to send query when searching for an empty string
2. Keyboard can be hidden after result receiving in search and lookup view.
fix remarks
Merge pull request #355 from ArkadiyTsoy/master

iOS 8 test
Merge branch 'master' of https://github.com/epam/road-ios-framework
Merge pull request #356 from Aledor/master

Behaviour of default json deserializator was changed
Migration from outdated WebService cache was added.
WebService cache migration: fix for cache tests.
WebService cache migration: small improvement in migration procedure.
Merge pull request #359 from ptiz/master

Initial version of a new WebService cache and its migration