Import into Unity 4.3.

* Change binary format of various asset files to plain text.
Change percentage options: 50, 65, 80, 90, 99.

With the old array, the difference between 50% and 60% was a likelihood
ratio of 1.5:1 while the difference between 90% and 99% was 11:1. This
way the gap is usually around 2:1 with 90% to 99% being an intentional
outlier.
Add per-generator frequency setting, QuestionsScript cleanup.

* Simplify QuestionsScript significantly. I don't see the value in
  pregenerating questions. It's not expensive.
* Change the way questions are selected significantly to accomodate
  question weight and user selected frequencies better. This is still
  somewhat experimental.
* Make tags work after restart. They weren't actually being applied
  unless you went to the tags ui and changed something.