Added support for acls.
Added support for acls.
New feature: Added UserGroup support.

1. Added helper class UserGroup for managing user group subscrptions.
Bug fixes for ACL integration

1. Fixed incorrect error code related issues.
2. Fixed incorrect parsing of APDevice, APUser and APObject.
Added support for events when user logged in status changes.
Added support for cache-control in file download.
Added environment support in api options.
Added forceUpdate support on SaveAsync()
Fixed syntax bug in starts\ends with queries.
Fix twitter login not working.

Fixed issue with incorrect oauth v1.0 data being passed to authenticate
API.
This was causing login with twitter to fail.
New feature: Support for get friends API.

Added support to get users who are friends of the given user for a
particular social network.
Merge branch 'acls'