Fix GFM in events

Fixes #2563

app/views/events/event/_common.html.haml

@@ -2,10 +2,9 @@
   %span.author_name= link_to_author event
   %span.event_label{class: event.action_name}= event_action_name(event)
   - if event.target
-    = link_to [event.project, event.target] do
-      %strong= truncate event.target_title
+    %strong= link_to_gfm truncate(event.target_title), [event.project, event.target]
   - else
-    %strong= truncate event.target_title
+    %strong= gfm truncate(event.target_title)
   at
   - if event.project
     = link_to_project event.project

app/views/events/event/_note.html.haml

@@ -21,4 +21,4 @@
 .event-body
   %span.event-note
     %i.icon-comment-alt
-    = truncate event.target.note, length: 70
+    = gfm truncate(event.target.note, length: 70)