[aur-dev] Some optimzation patches

[elij]

Here are some patches that optimze a few things:

- combine css for faster delivery (fewer tcp connections)
- minimize css (faster delivery, bandwidth reduction)
  note: originals are retained for later editing and re-minimization
- optimize png file
- specific image dimensions in a few places where they were missing
- move ie specific style (archnav bg image) to a separate stylesheet
  and include conditionally