Fixed bugs in DTDownloadCache
Fixed bugs in DTDownloadCache

- the return-cache-or-load-if-not-cached had a problem that would always load
- The completion notification is no longer sending the URL as object, but is transporting this in the userInfo dictionary

JaviSoto/DTFoundation,z8927623/DTFoundation,JaviSoto/DTFoundation,sbausis/DTFoundation,artifacts/DTFoundation,ShengQiangLiu/DTFoundation,programming086/DTFoundation,vlondon/DTFoundation,flatworld/DTFoundation,artifacts/DTFoundation,JasperYanky/DTFoundation,artifacts/DTFoundation,SanjoDeundiak/DTFoundation,Cocoanetics/DTFoundation,1yvT0s/DTFoundation,devontech/DTFoundation,flatworld/DTFoundation,JasperYanky/DTFoundation,nrcmedia/DTFoundation,SanjoDeundiak/DTFoundation,ywzw2013/DTFoundation