Added a page-rank-detection for sites.
If a site has a page-rank, it is displayed at site-analyzer.
Page-Ranks of 5 and higher get tagged, so we'll build up a list of
sites with high-pageranks. Since the feature is brand new, there is
not really much in there right now - but you might try to list all
sites having a Google-Page-Rank of 8 here: