AI 146953: am: CL 146951 CSS edits for docs;

  remove preliminary watermark;
  remove red color text for warnings;
  delete the caution class;
  use 1em top-margin only for elements nested in a DD, elements nested in regular
  LIs should only be a half em.
  Original author: smain
  Merged from: //branches/cupcake/...

Automated import of CL 146953