Move all PHP out of images/ subdirectory.
Comet tracker: Don't blast requests if comet server's down.
A little more spacing
Move scripts and stylesheets into their own subdirectories.

This is more typical in web frameworks, and allows us to drop
cacheable.php and serve scripts and stylesheets directly from
the web server.
Fix tarball.sh and move it and some files.
Standardize spelling of gray.
There are no .sh files any more.