added cleanup helper to server, looks for blocks in db that match the default world block and can be safely deleted
added cleanup helper to server, looks for blocks in db that match the default world block and can be safely deleted

satoshinm/NetCraft,polaco1782/Craft,konstructs/client,DanielOaks/Craft,fogleman/Craft,twetzel59/CraftNG,a101010/Craft,nathanial/VGK,dragonly/client,bdesemb/Craft,Henningstone/client,dragonly/client,satoshinm/NetCraft,dragonly/client,konstructs/client,nCore/Craft,a101010/Craft,UIKit0/Crust,UIKit0/Crust,nCore/Craft,fogleman/Craft,satoshinm/NetCraft,twetzel59/CraftNG,fogleman/Craft,satoshinm/NetCraft,bdesemb/Craft,satoshinm/NetCraft,polaco1782/Craft,omnus/Craft,nathanial/VGK,DanielOaks/Craft,naxIO/magebattle,a101010/Craft,omnus/Craft,naxIO/magebattle,Henningstone/client,twetzel59/CraftNG,omnus/Craft,Henningstone/client,konstructs/client,nathanial/VGK