CiviCRM OG Sync doesn't support the currently recommended release of Organic Groups for D7 (7.x-2.x)

Drupal's contrib Organic Groups module has been undergoing a major rewrite over the past year or so, and - at least as of this date - the 7.x-2.x is now listed as the recommended release for Drupal 7 on drupal.org (7.x-2.0-rc4). As of CiviCRM 4.2.7 (and also 4.3-alpha2), CiviCRM OG Sync only supports the 7.x-1.x branch of Organic Groups. Out of the box, a raft of undefined property and undefined index notices appear when trying to create and sync new groups, and group membership syncing is mostly broken. The main cause of the incompatibility seems to be in the 7.x-2.x approach is based on D7 entities rather than assuming groups will be 'nodes'. That means there are new parameters for some OG functions that are missing from the current CiviCRM OG Sync function calls.

Two other related issues are CRM-10422 and CRM-10231 - but since neither of those deal with the overall OG 7.x-2.x compatibility issue, I've created this new issue. Please forgive me if I've done wrong, and feel free to close/merge if necessary.