Merge branch 'file_lock_fixes' into 'master'

Subnav when viewing the locked files is not highlighted

Fixes https://gitlab.com/gitlab-org/gitlab-ee/issues/700

See merge request !488

app/views/layouts/nav/_project.html.haml

@@ -36,7 +36,7 @@
           Activity
 
     - if project_nav_tab? :files
-      = nav_link(controller: %w(tree blob blame edit_tree new_tree find_file commit commits compare repositories tags branches releases network)) do
+      = nav_link(controller: %w(tree blob blame edit_tree new_tree find_file commit commits compare repositories tags branches releases network path_locks)) do
         = link_to project_files_path(@project), title: 'Code',  class: 'shortcuts-tree' do
           %span
             Code