[archived] Remove border from link in top banner

There is a border on the div already, and it remove invalid CSS
Added background:transparent fallback for rgba
Remove background rule with no image

The intranet theme doesn't seem to use the background images of the Web Usability theme. Note that this isn't currently mentioned in http://wet-boew.github.com/wet-boew/demos/theme-gcwu-intranet/index-eng.html#hdrchgs

Fixes gh-905
Merge pull request #912 from nschonni/patch-1

Remove background rule with no image
Merge pull request #910 from berubs/issue903

[archived] Remove border from link in top banner
Merge pull request #911 from patheard/multimedia-csslint

Added background:transparent fallback for rgba