Add option for dataTables callbacks and jQuery plugin

- Callbacks for the dataTables plugin can now be specified in the WidgetUI
  class and any function that uses it
- oxfordCoursesWidget() jQuery wrapper added so that the functionality can
  be attached whenever wanted, and not just to .courses-widget-container
- Currently the options for the plugin just include the callbacks to send
  to dataTables
Rename callbacks, provide documentation

- Rename callbacks to dataTablesConfig for clarity
- Provide documentation on use of dataTablesConfig
- Make .courses-widget-container called upon by the jQuery plugin
-
Fix spacing on setUp line (so it is how it was before)
Merge pull request #4 from lokothodida/master

Add option for dataTables callbacks and jQuery plugin