Pixmap fix

[MaddTheSane]

These commits are based off of my attempts to get Zork Zero to work on my fork while also modernizing the code.
These include:

• flipping the context instead of the image.
• setting the initial pixmap size to 640x400.
• adding Objective-C properties and synthesize those that can.
• fixing the issue where inputStyle would never change due to always being nil, as well as retaining the new inputStyle via copying it (My code uses ARC, although copying it is to make sure the ZStyle wouldn't change. If the changing was desired, the copy can be replaced with a retain instead).