refs #1184 - added editing of true / false values in settings page

Feature #1184 - allow to save array based settings

this also moves the setting page to use inline edit

fixes #322 Ability to add custom variables and multiple values resovled
in a dynamic Hierarchally order

This commits introduces the ability to define variables per puppet
class.

additionally, each class can have multiple values, depends on the host
which is requesting that variable....

splitted setting default data from the migration
this allows to add new data and modify its defaults
improved settings UI a bit more
refs #100

fixes #100 - Setting is now a ActiveRecord object

This allows users to manage foreman settings via the UI.

the UI is a bit ugly, but works :)