added AFNetworking lib
implemented AFNetworking ref #2 #3
cancelling an ongoing search ref #2 #3
added segmented control to filter search results by category ref #2 #3
refactored search logic to its own method ref #2 #3
refactored urlWithSearchText: to urlWithSearchText:category ref #2 #3
added launch images close #2 #3
refactored: moved configureForSearchResult to SearchResultCell
loading images from web service using AFNetworking UIImage category ref #2 #3