implement manual event management and support for multiple speakers per event

app/views/proposals/_proposal_form.html.haml

@@ -4,6 +4,10 @@
 
     = f.input :subtitle, as: :string
 
+    = f.input :speakers, as: :select,
+      collection: options_for_select(@users.map {|user| ["#{user.name} (#{user.email})", user.id]}, @event.speakers.map(&:id)),
+      include_blank: false, label: 'Speakers', input_html: { class: 'select-help-toggle', multiple: 'true' }
+
     - if @program.tracks.any?
       = f.input :track_id, as: :select,
                 collection: @program.tracks.map {|track| ["#{track.name}", track.id] },
@@ -60,4 +64,15 @@
 
 
   %p.text-right
-    = f.submit 'Update Proposal', class: 'btn btn-success'
+    - if @event.new_record?
+      = f.submit 'Create Proposal', class: 'btn btn-success'
+    - else
+      = f.submit 'Update Proposal', class: 'btn btn-success'
+
+:javascript
+  $(document).ready(function() {
+    $('#event_speaker_ids').selectize({
+      plugins: ['remove_button'],
+      maxItems: 5
+    } )
+  });