Only pick when the model has pointer event listeners to hear it.
Test case for https://github.com/virtual-world-framework/vwf/pull/251.
Fix `does not have a valid behaviors array` warnings.

Prototypes with URIs not matching `RegExp( "^http://vwf.example.com/" )`
(including relative URIs) could appear ready before they were fully
constructed. References to the incomplete prototype would cause any
number of errors, including the `behaviors array` warning and different
sorts of references to `undefined`.

`kernel.createNode` allows lookups by node ID in addition to lookup by
descriptor, which the constructed node and its ID derive from, and by
URI, which the descriptor derives from.

`kernel.createNode` was not blocking out IDs of nodes that had begun
construction but had not yet completed. If a new node was created that
had a partically-constructed node as its prototype, and if the
prototype's URI matched its ID, then the new node would begin
constructing before the prototype was ready.

The solution is to not recognize a value as an ID if it would refer to a
node still being constructed.

See https://github.com/virtual-world-framework/vwf/pull/251.
Merge pull request #294 from virtual-world-framework/branch/mars-improvements

Branch/mars improvements
Merge pull request #295 from virtual-world-framework/mars-game-staging

Mars game staging
Fixes the hardcoded http which was causing cesium not to load over https

Fixes 2719
cherry-pick from PR 139
From another cherry-pick 2a439220c8a1b731c3a18af73d7f13aecddd3173
From cherry-pick 1efb2e9788df5fb51a6c27d54a46494b29abcf42
Adds line endings to make sure these files should load on each OS
Updates for API changes in b30
Updates the image and terrain providers
Updates the Cesium Viewer to the latest version
Fixes the reference to the ellipsoid
More b30 API changes