Linux

I improved the Makefile to make it more generalized. Now it will do a better job of detecting when things need to be rebuilt or not.

I also fixed some warnings raised by the -Wall flag in gcc, which could have been harmful on some systems. These errors included things such as allowing functions returning ints to go to the end of the control flow without returning anything.

Lastly, I randomized the seed of the rand() function, so now the game should be much more interesting to play.