add get(Type)Option methods
port some option uses
move lots of attr_ calls over to typed getOption
copy datahandler changes over from full-closure branch
move parseFloat_ method around
cleanup _calcYNormal
jsdoc
@protected
todo is done
Merge pull request #278 from danvk/typed-options

Typed options
copy over lots of changes from "shrink" branch.
fix up date formatting change
typos
another typo; all tests pass
delete dependencies
kberg review
lint
Merge pull request #280 from danvk/kill-code

Kill code
Merge pull request #279 from danvk/datahandler-cleanup

Datahandler cleanup
Fill in dygraph-extern.js.