Add method skeletons
Update Facebook, twitter, gigya methods, add callback queue functions
Include comments for new methods, document and and or methods
Add methods for login & create if needed fb and twitter
Merge branch 'f/social_unlinking' into development
Adding availability tag to methods and properties
Add availability section to all methods and properties for docs
Add logic/tests for querying equals/not equals empty string.
Add refresh token failure block and test with datastore api
Add method which accepts block that is executed upon token refresh failure.  Add tests for datastore api and core data async save/fetch methods.
Update token refresh failure method, add documentation
All tests passing, update token refresh failure block tests
add logic for facebook/twitterAccessTokenWithCreate
Update facebook/twitter login docs
Bump version in SDK to 1.4.0
Update changelog
Update change log with links
Merge branch 'release-1.4.0'
Update podspec
Fix typo