Make Message to Handler Constant Time

[HelloKitty]

Right now it takes O(n) time to find a packet handler for a particular packet. This allows for binding new handlers at runtime, allows for configuration easier and such and hotloading/reloading. Most useful for severs.

However, this isn't very useful for clients and with subcommands caching for routing isn't very reasonable or possible without hacks. We need an O(1) solution for faster packet handling.