Move abstract model to katello-common package

It's being used in both Katello and Headpin mode (at least form
app/lib/notifications/notifier.rb).
removing Fedora 17 releasers and residuum of older releasers
enabling SCL for katello
Removing Ruby 1.8 specific code
948754 - downcase the value for pulp url

When hostname has some capital letters, rubygem-oauth uses the
downcase version when creating the signature. On pulp side, the
original version is used, leading to signatures mismatch.
copyright update
Translations - Download translations from Transifex for katello-cli.
Translations - Download translations from Transifex for katello.
Translations - Update .po and .pot files for katello.
use pulp settings for default virtualhost

we are defining our own default virtualhost,
so pulps are ignored, this includes all there settings as well
without this, normal http repos will not work
apply_to_all for default_info
system groups - allow user to change env/view for selected systems

Prior to this commit, we added to the UI the ability for
a user to 'edit' the environment and content view associated with
all systems in a system group.  This commit will extend that so
that if the user selects a few systems from the group, they
can edit only those systems.
system groups - add test for handling edit on selected systems
Merge pull request #1858 from iNecas/bz/948754

948754 - downcase the value for pulp url
Merge pull request #1853 from xsuchy/pull-req-removef17

removing Fedora 17 releasers and residuum of older releasers
Merge pull request #1855 from lzap/turn-on-scl

enabling SCL for katello
Merge pull request #1863 from jlsherrill/translations

Translations update
Rails32 - Updating to fence off minitest task in production.
Fix dependency on a JavaScript engine
Merge pull request #1870 from iNecas/fix-missing-v8

Fix dependency on a JavaScript engine