Refactor StatefulPolymer

- add bindInputToState to element definition (instead when of every
instance is created)
- remove unnecessary stateEvent function
Perf: reduce resolution of all state chart events

StatefulPolymer uses events to add `stateFire.{event}` functions to a
polymer element. This can occur either upon each element declaration or
creation, so this change can reduce load times.
[svengali] test verifying statechart.events are deduped
Small refactor
[style] semibold is now 500.  Also eliminate unused monospace 600 font-weight
Add tab navigation to github repo and user

- Extract Card styles, remove unnecessary elements
- Add additional mock data
Remove AttrMunger
New: Issues tab for a Github Repo
Import github icons once

Added some docs about how the main views are rendered
Remove reference to ticker-github-branch