Updated benchmarking category on the wiki

As part of my PG East prep work, I just did a big overhaul of the
various benchmarking information available on the wiki and have tagged
all the relevant links into a separate category:
http://wiki.postgresql.org/wiki/Category:Benchmarking

Several of those were really difficult to find pages before; a couple of
them were linked to and needed but not created yet; and a few pages are
new ones I just wrote starter content for (TPC-H and SysBench are both
covered now).  There's enough new and formerly difficult to find pages
there now I felt it was worth mentioning here.

http://wiki.postgresql.org/wiki/Performance_Optimization was also
getting a bit large, so I removed the duplicated links from there.
Created a new page to hold all the database hardware links too.

--
Greg Smith  2ndQuadrant US  Baltimore, MD
PostgreSQL Training, Services and Support
greg@2ndQuadrant.com   www.2ndQuadrant.us