Factor and FactorTest are altered to contain multiple types of
error-specific identifications in the form of static instance fields.
parseInt() method no longer contains any printing lines; run is no
longer a static instance field, but rather a variable contained in main
and altered in main dependent on the return of QUIT_ID from parseInt(). 
Code is partially commented out, but fully readable.
Factor and FactorTest are altered to contain multiple types of
error-specific identifications in the form of static instance fields.
parseInt() method no longer contains any printing lines; run is no
longer a static instance field, but rather a variable contained in main
and altered in main dependent on the return of QUIT_ID from parseInt(). 
Code is partially commented out, but fully readable.