fixes #918 - API /usergroups won't output json

Signed-off-by: Marcello de Sousa <foreman-dev@area151.com>

fixed broken tests

added default order and paginations which
fixes #721
fixes #688

Fixes #366 - Redmine authorization port

This is a major feature which provides RBAC authorization within Foreman
a mental note to myself - never ever work on large commits

fixes #302 and all references to_label and to_s
removed references to all per_page settings as they are common now

fixes #271 - remove active scaffold plugin

Fixes #170 - implement usergroups

Added migration
Added tests
Added MVC files
Added the routes as well
Added the program logic and additional views
Added RESTful actions for update and create
Added validations to ensure that usergroup.name and user.login do not collide...