Blends web sentinel

Description of the project: In DebianPureBlends one key feature is the so called web sentinel which is featuring several parts like so called tasks pages (example from Debian Science), bugs pages (example from Debian Med), a so called thermometer (example from Debian GIS) and there might be other interesting features to be invented. The web sentinel is in principle based on data obtained from UltimateDebianDatabase but this is not yet consistently implemented and needs a partly or fully rewrite of the tools.