Add SDL manager class.

This include a 'test' method for the moment, but it will be removed.
This commit also includes a 'dot.bmp' resource for testing drawing images and moving them and stuff.
Add main.cpp and makefile

This is a very simple driver.

This makefile will include the appropriate frameworks and compile stuff.
To use, run the following in the command line as a single command:
make clean; make && make run