Make downloading map faster

[ghost-458]

Ideas:

• Preload map blocks in memory. Need to measure memory usage
• Separate websocket for getting data only
• Cache map requests
• Make reducer faster
• Perf test the various methods in components/map/

[vitalyrotari]

Also will be good to use ImmutableJS instead of base objects

[tylers-username]

This is my key focus as well. I'm hoping to get access to the source code for the maptile API server or find some documentation on how the rendering logic works based on player x,y,z.