Rename 'pe' -> 'fountains'
fuzzy: Add fuzzy_float type
fuzzy: Add fuzzy_color type
fuzzy: Fix the <type>_PROPORTIONAL variance calculation

Proportional variance is equal to:

  v = value * variance

So for a value of 100 and a variance of 0.1 (10%):

  v = 100 * 0.1 = 10
particle-engine: Use CoglColor for particles