Optimizations + Fixes (Summary)

This summary contains various kinds of optimizations and bug fixes I uploaded over the past weeks:

• fixed slow hint drawing in some situations (time-scaling issue)
• the level "Pharao's Darling" is actually correctly spelled "Pharaoh's Darling", with a trailing 'h', D'OH...
• after a level has been beaten, the RETRY button could still be clicked during a screen transition, which led to a false game state (messed-up level counter)
• better trench drag recognition: a car will probably never stuck in a trench again, while you still see it... For sure!
• smoother diamond particle effect
• better performance when drawing 100%-ink ball cars
• usability: clicking the hint button hint text now also shows the level hint: some players tried to click the hint text, instead of the button