Automatic merge from branch-5.3

Automatic merge from branch-5.3

* origin/branch-5.3:
  hide number of failing tasks on then project level page
  SONAR-6887 Improve message when missing revision or date on blame
  SONAR-6900 Add IT to simulate a build breaker strategy
  increase contract of leak period background
  improve display of leak period caption
  add tooltips for ncloc distribution chart
  love ie11
  improve scales of the bubble chart on the overview page
  fix tooltips on the overview treemap
  filter out empty components on the overview treemap
  normalize overview pages urls and titles
  improve code quality