Added support for command-line arguments, fixed detection of easy checkmate
-Engine now checks for command line arguments of gameMode, depth, and a debug flag for ease of testing. More args to be added as needed
-Changed the initial alpha and beta values in pvSearch to be equal to the constant scores for checkmate.  The engine now sees mates it was missing before, it still might not handle all cases though, more testing is required.
Added command line argument support for log level, added enum for log level