3rd Party Access

The purpose of the feature is to enable 3rd party reporting of viewability and VPAID events data raised by OVV by relaying them to a javascript object.
Third party vendors could subscribe to these events via javascript and send the relayed data to their servers.
1. I changed the tag injection to use a simple string and not XML
2. Also tested 2 tags on same event type, they work fine together. No overwrite