Big refactoring of registration

- Added datatable gem
- Addaed datatable to events, users (#422), registrations

app/views/conference_registrations/_registration.html.haml

@@ -0,0 +1,35 @@
+.row
+  .col-md-12
+    %h3
+      Registration for
+      = @conference.title
+- if current_user.proposal_count(@conference) > 0
+  .row
+    .col-md-12
+      %i
+        Please note: Registration is not automatically performed for speakers.  If you're scheduled to speak at the conference, you still need to register!
+.row
+  .col-md-12
+    = f.inputs name: 'Your Details' do
+      - if @conference.questions
+        = render partial: 'questions', locals: { f: f }
+      %br
+      - if @conference.use_supporter_levels? && @conference.supporter_levels.length > 0
+        = f.semantic_fields_for :supporter_registration do |reg|
+          = reg.input :supporter_level, as: :select, collection: @conference.supporter_levels
+          %span#supporter-link.help-block
+
+      - if @workshops.count > 0
+        =f.inputs 'Register to Workshops' do
+          = f.input :events, as: :check_boxes, label: false, collection: @workshops
+
+    = f.inputs 'Travel Info' do
+      = f.input :arrival, as: :string,  input_html: { value: (f.object.arrival.to_formatted_s(:db_without_seconds) unless f.object.arrival.nil?), id: 'registration-arrival-datepicker', readonly: 'readonly'  }
+      = f.input :departure, as: :string, input_html: { value: (f.object.departure.to_formatted_s(:db_without_seconds) unless f.object.departure.nil?), id: 'registration-departure-datepicker', readonly: 'readonly'  }
+
+:javascript
+    $("#registration_supporter_registration_attributes_supporter_level_id").change(function () {
+        var str = "";
+        #{generate_supporter_level_js @conference}
+        $("#supporter-link").html(str);
+    }).trigger('change');