Add cover-(type)-tile class to all tile templates.

This addresses the issue #189 for all the default tiles, but doesn't do it automatically for new tiles.
Merge remote-tracking branch 'upstream/master' into issue_189

* upstream/master:
  Fix some JSHint warnings on JS files
  Add message on template for empty carousel and enhance testing
  Add test for feature and line in change log (CC @rristow)
  Add/Removed the respective css-marker when the layout is edit/saved; Removed alert
  Warning to save when leaving layout tab

Conflicts:
	src/collective/cover/tiles/templates/carousel.pt
Update tests for the css class changes made in commit b52d5576a8cf2833ba7e05d73607606e7cce0954.
Robot tests: reload the compose page once more.

During some test runs this is needed, during others not.
Merge pull request #328 from warpr/issue_189

Add cover-(type)-tile class to all tile templates.
Bump up version of Selenium browser (refs. #332)

* version 2.36.0 fixes drag and drop by offset behaviour
* version 2.37.0 repackages with fix for Firefox native events on Linux

Let's pray!
Remove expected failure tag as RF test is passing again
Skip carousel tile RF test failing apparently because a Selenium regression

* Fixes #332
* Refs. #333