guide.html: add few links to online {iostat,sar}2pcp(1) pages
HTML 4.0 page validation for the tutorial content (5/4)
man pages: migrate perl database PMDA man pages to new scheme

Allowing simpler access to the man pages for online indexing.
Also move python PMDA man pages into src/pmdas now, planning
for PCP builds where no python is available (python too old).