Fix for infinite loop for scrolling left pane.

Will now try to detect that no items were loaded when scrolling was attempted.  Error will be thrown in that case.
Add the missing slingshot requirement
Merge pull request #834 from kbidarkar/fix-only-cv

Had the same problem  \w clean git clone, I think it is safe to merge.
Updated few more tests for 'only cv', promotions
Merge branch 'master' into manifest-delete3
Merge branch 'fix-only-cv' into manifest-delete3

Conflicts:
	src/katello/tests/providers/redhat.clj