Change exception caught to AttributeError.

Exception being thrown was not the one expected.  Need to do this to allow users that are not logged in to
view the graph.
Make sidebar refresh on login.
Make sure date_pickers are set whenever the graph controls are loaded.

This is on initial page load and on login.  There are no other places that I know of that render this
at this time.
Make start/end date format consistent.

getRanges() was using a totally different format than the date_picker.
Make saved graph render over the correct time frame.