0.9.1 drawing changes and c-stick oscilloscope

Changes for this release:

• If the program is running in interlaced mode, some drawing will be done with 2x1 pixels instead of 1x1. This is done because some crts don't look right when drawing 1x1 pixels. Progressive scan is unaffected by this change, and I plan to make this configurable in the future.
• You can now show the C-Stick inputs on both oscilloscope menus. Press Y to toggle between Analog Stick and C-Stick.
• Continuous oscilloscope menu can now be locked or "frozen" by pressing A. You still can't zoom in on the recording yet though.
• Continuous oscilloscope also got a vertical line indicating where the most recent data is being read from.