Report MAX_LOADS_TO_GPU throttling, return load promise and errors, fix node size with orthographic camera

[rhuitl]

• Return whether a node has been deferred to the next frame due to MAX_LOADS_TO_GPU

  This is a simple flag that signals to the caller of updatePointClouds() that the method has to be called again to finish loading of nodes.

• Report failures when loading node data and return node load promises to the caller

  Completing the promise chain to resolve a promise when the web worker has posted back the decoded node. Fix house keeping of the number of loading nodes in case of errors (e.g. 404 on a bin or hrc file).

[rhuitl]

Addressed your comments, thanks!

[hccampos]

@rhuitl released just now in v0.0.19