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.
Merge pull request #328 from warpr/issue_189

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