Refactor pre-lesson2.
Lesson two execution

Able to execute either a) sdl or b) lesson2 based on command line
options.
Lesson2 complete.

Learned that the screen must be initialized before the images can
be loaded - at least that seems to be how the application is acting.

Also, I loaded up some new files for this, to make the images load
like the tutorial.
Merge pull request #3 from paulsalcido/lesson2

Lesson two completed.