Merge branch 'issue-2216' into 'master'

Diff colors on MR Discussion like on Changes-tab

Fixes #2216

# Before
![Screen_Shot_2015-08-06_at_21.44.58](https://gitlab.com/gert/gitlab-ce/uploads/ed5935e0713dd58f9cd4b17a1fecaa86/Screen_Shot_2015-08-06_at_21.44.58.png)

# After
![Screen_Shot_2015-08-06_at_21.44.33](https://gitlab.com/gert/gitlab-ce/uploads/0816360afcc7cf860d2eadf8dd63b49e/Screen_Shot_2015-08-06_at_21.44.33.png)

See merge request !1108

CHANGELOG

 Please view this file on the master branch, on stable branches it's out of date.
 
 v 7.14.0 (unreleased)
+  - Fix coloring of diffs on MR Discussion-tab (Gert Goet)
   - Fix "Network" and "Graphs" pages for branches with encoded slashes (Stan Hu)
   - Fix errors deleting and creating branches with encoded slashes (Stan Hu)
   - Always add current user to autocomplete controller to support filter by "Me" (Stan Hu)

app/views/projects/notes/discussions/_diff.html.haml

@@ -12,18 +12,19 @@
     .diff-content
       %table
         - note.truncated_diff_lines.each do |line|
+          - type = line.type
           - line_code = generate_line_code(note.file_path, line)
-          %tr.line_holder{ id: line_code }
-            - if line.type == "match"
+          %tr.line_holder{ id: line_code, class: "#{type}" }
+            - if type == "match"
               %td.old_line= "..."
               %td.new_line= "..."
               %td.line_content.matched= line.text
             - else
-              %td.old_line{class: line.type == "new" ? "new" : "old"}
-                = raw(line.type == "new" ? " " : line.old_pos)
-              %td.new_line{class: line.type == "new" ? "new" : "old"}
-                = raw(line.type == "old" ? " " : line.new_pos)
-              %td.line_content{class: "noteable_line #{line.type} #{line_code}", "line_code" => line_code}= raw diff_line_content(line.text)
+              %td.old_line
+                = raw(type == "new" ? " " : line.old_pos)
+              %td.new_line
+                = raw(type == "old" ? " " : line.new_pos)
+              %td.line_content{class: "noteable_line #{type} #{line_code}", "line_code" => line_code}= raw diff_line_content(line.text)
 
               - if line_code == note.line_code
                 = render "projects/notes/diff_notes_with_reply", notes: discussion_notes