added container div (to allow main panel centering), moved up mainBodyGuest div, and added bannerSpacer div as part of major website facelift
added container div (to allow main panel centering), moved up mainBodyGuest div, and added bannerSpacer div as part of major website facelift

paleobiodb/pbdb-new,paleobiodb/pbdb-new,paleobiodb/pbdb-new,paleobiodb/pbdb-new,paleobiodb/pbdb-new