Fixes #6551/BZ1112644: show add/remove content hosts if user able

The permissions that show and hide the UI for adding/removing
content hosts to/from a host collection were incorrect.  This commit
fixes those permissions.

http://projects.theforeman.org/issues/6551
https://bugzilla.redhat.com/show_bug.cgi?id=1112644
fixes #6329 - toggle label content view/puppet environment, toggle show/hide installation media on new host form
Fixes #6411 - filter content param in CU BZ1111484

The content param in the content_uploads action is causing
the log to fill up with garbage since content is binary.  This
filters the log so that the content_uploads the content param is
filtered.
Merge pull request #4364 from dustint-rh/filter_log_content_using_foreman_katello_plugin

Fixes #6411 - filter params by path BZ1111484
Merge pull request #4413 from waldenraines/6551

Fixes #6551/BZ1112644: show add/remove content hosts if user able
fixes #6592 / BZ 1118895 - Activation Keys UI: replace 'System' references

In the UI, System should be replaced with Content Host on both the
new & edit screens for activation keys.
fixes #6593 / BZ 1118897 - Host Collections - fix crosslink to edit env and view
Merge pull request #4419 from bbuckingham/issue-6593

fixes #6593 / BZ 1118897 - Host Collections - fix crosslink to edit env and view
Merge pull request #4418 from bbuckingham/issue-6592

fixes #6592 / BZ 1118895 - Activation Keys UI: replace 'System' references
Merge pull request #4325 from isratrade/6329

fixes #6329 - toggle label content view/puppet environment, toggle show/hide installation media on new host form