re-design bars and traits values

[stolsky]

• [ ] remove min & max in Trait
• [ ] Trait = { now: number, sd: number, mr: number }
  • how to define lower and upper bounds of now value
  • mean is current now
• [ ] Bar = { min: number, now: number, max: number, sd: number, mr: number }
  • mean is current max
• [ ] remove rate in Bar
• Bar is extended Trait
  • adds only functionality

mr = mutation rate sd = standard deviation