#118 Flexible Tier heights

[Brian O.]

Tier heights:

- Tier height should be in TierProperty--ideally, should be controllable
in tiers file. Maybe three different variables for height of start/stop
codons, annotations, and results.

- Make annotations a bit taller than features

- I tried making TierManager:setupTiers check if the tier it's setting
up is type Annotation, and if so, adding 5 to the drawSpace. This worked
temporarily, but it forgot about it when the tiers were resized.

- "Reset views" doesn't reset tier heights to default--should it?
(Not simple to do because of the way tier heights are controlled)