Entity Constructors Made Modular

[WELDWorks]

Overload Entity-inheriting classes' constructors so that different instances may have different internal algorithms; two cities, for example, may have different rates of growth and decay.

Standard constructors (no parameters) should be taken to mean default standards.

ALL NON-DEFAULT RATES SHOULD BE STORED IN GLOBALCONSTANTS.JAVA, AND PASSED TO NEW INSTANCES AT THE TIME OF THEIR INITIALIZATION.