Fix tick flicker.
First cut of CS scales code.
Time scales work from days on down.
First cut at day resolution for ticks.
Make day resolution more correct.
Handle days too close together.
Add months scale.
Remove missing scale level.
Add better toString() for scales.
Make all ticks in GMT.
Add comments.
Remove redundant month scale.

Also added comments indicating interval ranges for the various time
scales.
Remove some old code and comments.
Fix formatting transitions.

That turned out to be easier than expected.
Use datetime formatting only for datetime axes.

Pretty hacky.
Fix whitespace.
Change naming scheme.
Clean up date functions.
Pull out some local functions.
Clean up a few map()s.