Prevent distorted badge images and program logos

Fixes distorted badge images and program logos by using `max-width` and
`max-height` instead of forcing `width` and `height`. Includes fix for IE8
`max-width` bug in `display:table-cell` element used for centering.
Introduces `.no-src` class to handle default images for programs or
badges without images.

Things to note:

  1. the longest side of the logo should be &gt;300px
  1. small images **are not** sized up
  1. large images **are** sized down

Example of over- and under-sized logos: <img src="http://f.cl.ly/items/0P2K0M0V1R1t2s2A0R0l/13.png" >