WIP: custom date/time picker for section parts

This is only partially working, but wanted to get it pushed up.

Issues:

- TurboLinks is messing with the initialization, so the component
  doesn't always initialize unless you do a hard refresh of the
  page

- The default format for a Rails datetime object isn't in a format
  that the datetimepicker understands, so it thinks existing
  start_at times are invalid
Merge branch 'master' of github.com:cit-jmu/workshop
ignore vim swp files
Fixed bug in setting the :role for a User

I had made a change to the users#update controller action to protect the
:role attribute, but was pulling the :role from params[:role] rather
than params[:user][:role], so it was not getting set.

Thought of a cleaner solution anyway to permit it, but then remove
it from the attributes has unless the user can? :assign_permissions.