Package-level declarations

The build area class is responsible for tracking the currently-rendered map of a given player. Everything sent via world entity info is tracked as relative to the build area.

An interface used for info protocols for the purpose of re-using an object. This is handy in cases where the objects themselves are heavy, and deallocating and reallocating the object itself might become too costly, so we utilize a soft reference pool to retrieve older objects and re-use them in the future.