* determine cloud url dynamicaly
* Fix specifying the cloud URL from a meta tag
* no protoptye for Cloud.knownDomains
* Tweak the location of where SnapCloud is created.
Note - we want to call determineCloudURL once document.head is available, so it is best
to do that in the onload callback for safety.
* Move initialize to cloud.js; simplify logic a bit
* move SnapCloud to this.cloud on IDE_Morph
* update eisenberg library