Multithreading map architecture

Two design problems of Manaserv are:

1. It doesn't do any parallelization, and who does still run a server with just a single CPU core?
2. When there is a segmentation fault, the whole server goes down and needs to be restarted manually

A perfect unit of parallelization are the map instances, because there is few communication between them. Also, when one of the map threads crashes, you could just have the main process restart this one without concerning the others.