Due dates have been incorporated. But turndown is not yet computed.  Related to #19
Change back to minified high charts source.
Made sure date ranges are acceptable before getting into turning things on and off.  Fixes #28.
Cleaned up code in Hghcharts directive a little bit. Fixes #32.
When a series is hidden or shown, also hide/show it's plot lines. Fixes #27.
Hidden series adjusts based on series visibility.  Actually Fixes #28.
Clamp start and due dates to day boundaries.
No more overlapping plot lines, at least on specific days.  But you can't please everyone. Fixes #29.
Merge branch 'due-dates'

* due-dates:
  No more overlapping plot lines, at least on specific days.  But you can't please everyone. Fixes #29.
  Clamp start and due dates to day boundaries.
  Hidden series adjusts based on series visibility.  Actually Fixes #28.
  When a series is hidden or shown, also hide/show it's plot lines. Fixes #27.
  Made sure date ranges are acceptable before getting into turning things on and off.  Fixes #28. Cleaned up code in Hghcharts directive a little bit. Fixes #32.
  Change back to minified high charts source.
  Due dates have been incorporated. But turndown is not yet computed.  Related to #19