Asynchronous Cached Entities

Hooks to allow entity caching, and to separate out procedurally loaded elements from storage backed data trees so that platforms that have the ability to batch query can utilize it.

X-Requested: CommCare, JavaRosa

Relies-on: inline_entity_tiles
Whoops! Good catch. I actually wanted Queue's here, but 1.3 j2me doesn't have them so I went back to Vectors and missed the declaration. fixing now.