All main simulation management methods implemented.
Major code refactoring.

Removal of force function type and implementation of dedicated force
function in separate source files. Removal of heuristic function type
and implementation of dedicated heuristic function in separate source
files.
Updates to constants.h
Refactored simulation creation methods.
Updates to simstats
Added vector copy method.
Cleaned out unused portions of tests. Will reimplement tests soon.
Added necessary information for input files and general instructions for doing so.
Added dedicated force function files and methods.
Added dedicated heuristic files and methods.