welcome: redesign the front page

We are now using Socialicious for social icons, see:

  https://github.com/shalinguyen/socialicious

Licensed under the MIT license.

Signed-off-by: diditclear <didyourupgradeclear@gmail.com>
itinerary_controller: fix incorrect error message on airport page

Signed-off-by: diditclear <didyourupgradeclear@gmail.com>