* Extracted PollFD manipulation and nonblocking socket configuration
into helper functions
* Replaced the connections list with an unordered_map
* Dynamically grow the number of PollFD structures with realloc()
With these changes done, the server's CPU usage is completely diminished
from its old average of ~47% to ~0.07%, with occasional spikes up to ~14%.
* Deleted empty Player.cpp
* Moved the helper functions from the obsolete CNStructs.cpp into
main.cpp and deleted it
* Renamed CombatManager to MobManager, as that will likely become it's
main focus soon
Also changed output buffer in pcAttackNpcs() from dynamically to
statically allocated. This in itself is temporary as I have a better
idea as to how we can allocate buffers with a bit less boilerplate.
