Add icon; carousel changes.

Added Rock Icon:
 - added as favicon (probably a hack?)
 - Added to navbar-brand.  Needed to update .navbar-brand sizing and
   padding to make it centered.  There's probably better ways to do this.
Updated Carousel to fixed height:
 - Carousel images are now fixed at 500px height and a fixed aspect ratio.
   This allows images to retain their intended aspect ratio.
 - TODO: Need to center certain images, instead of merely showing the left
   of wide images
Replaced Tom Short with Faithwalkers:
 - Added faithwalkers image and text instead of Tom Short
 - NOTE: Faithwalkers image is narrow and looks terrible when stretched.