Better Image Navigation

Had a bit of time to kill just now and have made some improvements to image navigation.

Basically, added some right/left arrows and AJAXified them so one can scroll through the thumbs before selecting one to view in more detail. It works with or without Javascript (fallback to usual page loading), but really... what are you doing running a browser without it?

Also squashed the header a bit when viewing images... saves screen real estate.

You'll need the new CSS or this won't look very pretty - do a hard refresh (control-R usually).

Now... to fix that small issue when you are sometimes switched between galleries when viewing and image tagged in more than one gallery (which has been there for a loooong time). Too easy