Fixes 3872: Provides a better customizable application layout that
conforms to HTML5 best practices.

This change aims to provide a more customizable application layout by first
splitting the base layout, menu and content out into their own view files.
The base layout provides generic hooks and only the most basic common data
such as application javascript, stylesheets, inclusion of the menu and auth
token. Javascript inclusion is moved to the bottom of the page for page
loading efficiency. Further, all inline scripts are placed into the same
tag for browser loading efficiency. Stylesheet and generic head hooks are
split out for better readability. Lastly, this includes some updates to the
overall layout by including current HTML5 best practices for detecting and
declaring the doctype for polyfills and proper meta tags.
fixes #3889 - don't reload nested lookup keys during render, so validation errors aren't lost
fixes #3752 - move data population from migrations into seed script
Fixes #3811 updating to bootstrap 3
fixes #3811 - merge with new layout
refs #3811 - foreman.spec: change twitter-bootstrap-rails to bootstrap-sass
fixes #3178 - add ability to apply a virtual hardware template at hostgroup level