Fixes #6827/BZ1124607: hide CH Product tab if you lack permission.

The Content Host Product tab was being shown even if you did not
have the correct permissions to view that page.  This commit hides
the tab if you cannot view the page.

http://projects.theforeman.org/issues/6827
https://bugzilla.redhat.com/show_bug.cgi?id=1124607
Merge pull request #4500 from waldenraines/6827

Fixes #6827/BZ1124607: hide CH Product tab if you lack permission.
fixes #6846 - correct link to hypervisor's content hosts
Fixes 6807/bz1103033 - Host Collection UI rows refresh code

Previously the content host counts in the rows of host collection index table
would not get updated. So for example if the host collection had 5 CH's and 6 th on got added
the updated CH count would not get reflected in the Host Collection index page. This
commit fixes that
Merge pull request #4506 from thomasmckay/6846-crosslink

fixes #6846 - correct link to hypervisor's content hosts
Merge pull request #4496 from parthaa/host-collection-fix

Fixes 6807/bz1103033 - Host Collection UI rows refresh code