Added parser interface
Restructured main according to parser interface, now plugin technology
Implemented Ebay URLs
Minor column resizings
Implemented all page scanning for Ebay (not only first page)
Bugfix in both parsers: Check for null HTMLNodes
Bugfix in EbayParser: Wrong URL generation
Added Agility pdb file to references (for profiling purposes)
Experimented with multi-threading in Main, currently commented out because
it didn't work