Merge branch 'search-on-groups-is-ugly' into 'master'

Change placeholder text to just 'search'

Fixes #13168 

![Screen_Shot_2016-02-04_at_12.30.16_PM](/uploads/ca3c5549abeedce99d693606135d7428/Screen_Shot_2016-02-04_at_12.30.16_PM.png)


See merge request !2711

app/helpers/application_helper.rb

@@ -169,18 +169,6 @@ module ApplicationHelper
     Gitlab.config.extra
   end
-  def search_placeholder
-    if @project && @project.persisted?
-      'Search'
-    elsif @snippet || @snippets || @show_snippets
-      'Search snippets'
-    elsif @group && @group.persisted?
-      'Search in this group'
-    else
-      'Search'
-    end
-  end
-
   # Render a `time` element with Javascript-based relative date and tooltip
   #
   # time       - Time object

app/views/layouts/_search.html.haml

 .search
   = form_tag search_path, method: :get, class: 'navbar-form pull-left' do |f|
-    = search_field_tag "search", nil, placeholder: search_placeholder, class: "search-input form-control", spellcheck: false
+    = search_field_tag "search", nil, placeholder: 'search', class: "search-input form-control", spellcheck: false
     = hidden_field_tag :group_id, @group.try(:id)
     - if @project && @project.persisted?
       = hidden_field_tag :project_id, @project.id