- fixed fontawesome icon rules in buttons, cards, sidebar & smallbox
- added calc for `.content-wrapper` min-height
- added layouts: top-nav, boxed & sidebar collapsed
- fixed mailbox attachment size
- added bg-*, navbar-*
- updated demo.js
- updated sidebar in demo files (added layout options)
- added autoprefixer to fix browser specific css changes
- added css sourcemap for adminlte.min.css