Merge remote-tracking branch 'upstream/pull/2491'

diff --combined app/assets/stylesheets/common.scss
index 3f2a151ab913b71d53e8579119c1373d5784c367,ccb46005e0090612b6e5d543656327a8339822fc..3d013339df6e6d370247192d84ad93fcf9bb13bb
--- 1/app/assets/stylesheets/common.scss
--- 2/app/assets/stylesheets/common.scss
+++ b/app/assets/stylesheets/common.scss
@@@ -541,6 -541,7 +541,7 @@@ body.compact 
    #sidebar {
      float: left;
      width: $sidebarWidth;
+     background: #fff;
  
      #sidebar_loader {
        display: none;
@@@ -2269,6 -2270,12 +2270,6 @@@ a.button 
  
  .richtext,
  .prose {
 -  h1, h2 {
 -    padding-bottom: $lineheight/2;
 -    border-bottom: 1px dashed $grey;
 -    margin-bottom: $lineheight/2;
 -  }
 -
    code {
      font-size: 13px;
      background: $lightgrey;