Update changelog.txt
Assert that OAuth1 credentials are not given as null.
Capture OAuth 2 error callback details and present as a Map in the model. SOCIAL-358
Capture OAuth 2 error callback details and present as a Map in the model. SOCIAL-358
Handle OAuth 2 authorization callback errors in ProviderSignInController. SOCIAL-358
Update changelog.txt
Merge pull request #109 from habuma/master

Sync-up PR for changes to fix SOCIAL-358