fixes #3960 - wrap APIv2 errors in an "error" node
fixes #2866 - Changing a hostgroup name doesn't update associated Smart Variable matchers
fixes #4188 - api/v2/status incorrectly shows api_version: 1
fixes #4186 - db:seed fails when install media exists with same URL
fixes #4189 - Facts charts are not rendered
fixes #4005 - ensure standalone Rabl.render works outside of a controller
fixes #4178 - updating i18n extracting rake task and makefile
fixes #3553 - add "except" option to prevent puppet class import to select types of import
Fixes #4196 "Power ON this machine" disappeared for new VMWare hosts
Usergroup roles support

Working version which currently breaks a lot of tests however is ready
for testing by devs. There are still things to improve. Also we enable
users that can edit usergroups a privilege escalation atm.
Fixed tests
Add cycle detection and prevention in usergroups
Add migration for caching existing user roles
Fixed issue for redundant structures
Recache after remove

The only way to keep correct cache without complete recalculation or
having complete paths stored
With this we don't even need user_membership caching
Usergroup membership caching
Admin flag can be assigned to usergroup
Small refactorings
Roles design