Add basic templates and views for adding a new event
Add unique_together for group and title.

Since we use the title to generate the slug, which must be unique for the
Group, it makes sense to have group also be unique with title
Use Django-floppyforms for better field rendering

A better form library was needed for the following:
 - Use of inputs of type=date and type=time, which we want on mobile
 - Adding required to the input, to avoid round trips to validate
   missing fields
 - Adding placeholder text to inputs
Add Bootstrap JS and CSS.

The CSS file will likely be removed fairly soon, in favor of using the
SASS version of Bootstrap.
Validate that event begin time is before end time
Add custom Modernizr.  Only brings in the loader and inputtypes
Add polyfill for date and time inputs on unsupported browsers

There's quite a bit going on here:
 - Brings in the Bootstrap-datetimepicker library for polyfilling
   https://github.com/Eonasdan/bootstrap-datetimepicker
 - Adds a settings.js file, as a centralized way to make
   dynamic information available to the client
Fix lint