Faster screen updates - fetching pixels

[GoogleCodeExporter]

It's possible to refresh the view faster.

Problem: The graphics is stored in C64 format internally. Each pixel is fetched 
via an expensive virtual call. This is extra costly when zooming out a large 
image.

Solution: Implement a more optimized bulk pixel fetch the MFC painter can use.

Original issue reported on code.google.com by [email protected] on 19 Feb 2014 at 12:35