Fixes #3811 updating to bootstrap 3

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...

fixes #3790 - Added support for isolated engine to foreman menu

fixes #2741 - remove dash from -%> to %>

fixes #2526 Favicon only shows up if foreman is deployed in the root context

fixes #2511 Footer should be replaced with an about page

fixes #2420 - extract strings for i18n from JavaScript, various i18n fixes

fixes UI errors in trend pages

new top-bar navigation design and a new login page

Feature #2368 - i18n extracting strings