Post-jam Update

Major updates that I've been putting together for after voting on Trijam #87 ended.  This includes all new graphics and improvements to gameplay from the original jam version.  Details below:

• Switched from the cube to a car model with detailed tires
• Improved vehicle physics to make it a little easier to keep a drift going
• Added RPM bonus in addition to the existing speed bonus
• Added gauges for RPM and Speed
• Swapped the checkerboard material for pavement
• Increased the score and time sizes and made them both left-oriented
• Improvements to UI flow and layout
• Added a local high-score chart (Scores persist in the windows and linux versions, but only last while the window is open in WebGL)