AlloyUI theme, Conrol Panel, and image updates

This pull request includes chapters 1 and 2 of the User Guide. These chapters were edited to compensate for the Portal reformatting that is taking place for 6.2. I also updated all of the images in these chapters for 6.2 (except for three, which are not able to be updated at this time). The images that are not updated in this cycle are commented out in the markdown so we know which images are old.