Update button methods to handle Terminate instance button

https://bugzilla.redhat.com/show_bug.cgi?id=1122039
Added support for buttons from Cloud Tenant summary screen.

- Added support for buttons when going to list of Instance/Images thru relationships from Cloud Tenant summary screen.
- Added spec tests for routes under cloud tenants and spec test to verify that button method is added to cloud tenant controller.
- Fixed a typo in edit_form_buttons view for reset button.

https://bugzilla.redhat.com/show_bug.cgi?id=1138838
https://bugzilla.redhat.com/show_bug.cgi?id=1138188
Updated helper method name

https://bugzilla.redhat.com/show_bug.cgi?id=1122039
Added missing icon

https://bugzilla.redhat.com/show_bug.cgi?id=1133849
Merge pull request #553 from epwinchell/cloud_tenants_icon

Added missing icon
Merge pull request #551 from bmclaughlin/terminate-via-quadicon

Update button methods to handle Terminate instance button
Merge pull request #545 from h-kataria/fix_cloud_tenants_relationship_buttons

Added support for buttons from Cloud Tenant summary screen.