Update Turbolinks, load additional assets only on request, fix JS

Signed-off-by: Sebastian Serth <Sebastian.Serth@student.hpi.de>

app/views/exercises/index.html.slim

@@ -36,7 +36,7 @@ h1 = Exercise.model_name.human(count: 2)
           td.public data-value=exercise.public? = symbol_for(exercise.public?)
           td = link_to(t('shared.edit'), edit_exercise_path(exercise)) if policy(exercise).edit?
           td = link_to(t('.implement'), implement_exercise_path(exercise)) if policy(exercise).implement?
-          td = link_to(t('shared.statistics'), statistics_exercise_path(exercise)) if policy(exercise).statistics?
+          td = link_to(t('shared.statistics'), statistics_exercise_path(exercise), 'data-turbolinks' => "false") if policy(exercise).statistics?
 
           td
             .btn-group
@@ -44,7 +44,7 @@ h1 = Exercise.model_name.human(count: 2)
               span.caret
               span.sr-only Toggle Dropdown
               ul.dropdown-menu.pull-right role="menu"
-                li = link_to(t('shared.show'), exercise) if policy(exercise).show?
+                li = link_to(t('shared.show'), exercise, 'data-turbolinks' => "false") if policy(exercise).show?
                 li = link_to(t('activerecord.models.user_exercise_feedback.other'), feedback_exercise_path(exercise)) if policy(exercise).feedback?
                 li = link_to(t('shared.destroy'), exercise, data: {confirm: t('shared.confirm_destroy')}, method: :delete) if policy(exercise).destroy?
                 li = link_to(t('.clone'), clone_exercise_path(exercise), data: {confirm: t('shared.confirm_destroy')}, method: :post) if policy(exercise).clone?

app/views/exercises/show.html.slim

@@ -1,6 +1,9 @@
 - content_for :head do
-  = javascript_include_tag('http://cdnjs.cloudflare.com/ajax/libs/highlight.js/8.4/highlight.min.js')
-  = stylesheet_link_tag('http://cdnjs.cloudflare.com/ajax/libs/highlight.js/8.4/styles/default.min.css')
+  // Force a full page reload, see https://github.com/turbolinks/turbolinks/issues/326.
+     Otherwise, code might not be highlighted correctly (race condition)
+  meta name='turbolinks-visit-control' content='reload'
+  = javascript_include_tag(asset_path('highlight.min.js', type: :javascript))
+  = stylesheet_link_tag(asset_path('highlight-default.css', type: :stylesheet))
 
 h1
   = @exercise

app/views/exercises/statistics.html.slim

@@ -1,4 +1,8 @@
-script src="http://labratrevenge.com/d3-tip/javascripts/d3.tip.v0.6.3.js"
+- content_for :head do
+  // Force a full page reload, see https://github.com/turbolinks/turbolinks/issues/326.
+     Otherwise, code might not be highlighted correctly (race condition)
+  meta name='turbolinks-visit-control' content='reload'
+  = javascript_include_tag(asset_path('d3-tip.js', type: :javascript))
 h1 = @exercise
 
 = row(label: '.participants', value: @exercise.users.distinct.count)
@@ -32,8 +36,8 @@ h1 = @exercise
     .graph-functions
     div#chart_1
     hr
-    /div#chart_2
-    /hr
+    div#chart_2
+    hr
   .table-responsive
     table.table.table-striped.sortable
       thead