Added tetromino class base

Added basics for tetromino class.
Flushed out tetromino, linked with board

Added more functionality to the tetromino class, including tetromino
types. Also began linking the class into game_board.
Moving tetros to derived classes

In the process of moving the tetrominos into seperate derived Tetromino
classes.
Continuing move of tetromino derived class

Added print and initialize functions to the derived classes.
Moved main Learntris file out of src.

Also added Makefile