Added a better working example of animation!

Rewrote (improved) parts of the draw_frame method in the Images class
to allow specific widths to be used.

In the example you can see the widths are stored in an array. In the
future we will keep these stored in a text file and load them in simply
with a vector.

Also added stable FPS in the main file.

Note well the differences in FPS and animation updates. Limiting
animation updating does NOT affect the FPS at all. If the animation has
not updated yet, the game will still re-render the image at its current
frame (as many times per second as set).