[Hps] confluence cleanup and reorganization

[Nelson, Timothy Knight]

Dear Collaborators,

As the HPS webmaster by default, I've decided to take the bull by the horns and do some cleanup and reorganization of the HPS confluence pages, which have become increasingly chaotic.  If you find yourself digging for something, try using the search box, and please bear with me while I try to get it into shape.  Once I'm largely done and things settle down, I'll let you know.

Cheers,
Tim