Remove unused code
Fix improper scaling @ HV != 1280

Previously, entities would render at different relative sizes when the
rendering resolution was altered. Now, they should render at the proper
relative sizes, regardless of resolution.

This value is hard-coded because it represents the screen width at which
the sprite was created (sprites are pixel perfect for 1280x720).
Different values can be used to achieve pixel accuracy when different
screen widths are used when creating image assets.