add menu_item model
menu_items admin CRUD
show menu_items hierarchically
delet page uri field
move admin pages controller in menu_items namespace
Merge branch 'develop' of github.com:kaize/castle into feature/menu-104

Conflicts:
	app/controllers/web/page_controller.rb
	app/models/page.rb
add show menu_items in navigation
add nav for pages
add locales for menu_items
add sorting pages with errors
fixes sortable for pages
fixes sorting
fixes dependent destroy 114
add search for pages
delete activity and page_activity
fixes show active menu_items
fixes bug 121, replace link to button
fixes collection parent for menu_items
fixes bug 121, change view index page for admin
fixes view menu items for admin