Finalize CONNECT 5.3 branch and prep repository for future code contributions

Completion criteria:

• DO NOT create new tags

• Rename GA tags to appropriate CONNECT 5.3 release tags

• Upload all 5.3 binaries to appropriate location for community download (5.3 wiki)

• Finalize CONNECT 5.3 branch - released code that should never be updated

• Perform all activities necessary as though preparing for the next CONNECT release cycle

QA:

Make sure branch is created and build passes on it locally.