[FEATURE] Bring twbs & fontawesome via composer

Brings Bootstrap 3.2 and FontAwesome 4.2 dependency for require-dev.

Resolves: #61454
Releases: 6.3
Change-Id: I07e9258eecdef509825c6122096ff2f1c5e7fca7
Reviewed-on: http://review.typo3.org/32656
Reviewed-by: Thomas Maroschik <tmaroschik@dfau.de>
Tested-by: Thomas Maroschik <tmaroschik@dfau.de>
Reviewed-by: Nicole Cordes <typo3@cordes.co>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Markus Klein <klein.t3@reelworx.at>
Reviewed-by: Jo Hasenau <info@cybercraft.de>
Tested-by: Jo Hasenau <info@cybercraft.de>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>