Merge branch 'leipert-improve-ansi2html' into 'master'
Improve job log rendering performance See merge request gitlab-org/gitlab-ce!31262 (cherry picked from commit eb2d4adf) 6b45d85e Prevent empty classes in ansi2html conversion 5366c89b Fix deep DOM tree problem in ansi2html d1f4d8c7 Improve size of rendered job trace