Incremental blueprint loading [IRRATIONAL]

[moonheart08]

As of now, the game ends up effectively hanging until blueprints finish loading. The best solution for this, of course, is to make the entire process incremental and put a cap on it's ability to munch tick time, which means

• Incremental deserialize and/or deserialize at game load and cache the result
• Incremental entity creation when converting the deserialized map to actual entities
• Making sure nothing can dunk on the above process accidentally by trying to do shit before the map is fully loaded

[PJB3005]

Deserialization should probably be completely parallely threadable. Main thread access of entity/component data will need to be incremental but that'll be fine.

Making sure nothing can dunk on the above process accidentally by trying to do shit before the map is fully loaded

Pausing can handle this, probably.