define translated find_by_<attr>_<locale> methods on class

were defined on instances

e.g.: Page.new.find_by_slug -> Page.find_by_slug
allow empty urls to be passed to pages controller

allows host apps to define root :to => 'kuhsaft/pages#show' without the need to define a homes controller
spec show action with empty url
update changelog
make locale mandatory in url
Merge branch 'bugfixes/find_by_on_class'

Conflicts:
	CHANGELOG.md
update changelog
Merge branch 'features/simplify_routing'

Conflicts:
	CHANGELOG.md
bump version
Update CHANGELOG.md
Merge branch 'master' into features/optimize_redirect_page

Conflicts:
	CHANGELOG.md
	app/controllers/kuhsaft/pages_controller.rb
	spec/controllers/kuhsaft/pages_controller_spec.rb