Added table view with images
myviewcontroller
add placeholder
add AFNetworking. Use AFImageRequestOperation
add progress view and indicator view
cancel image operation on new url.
Fix wrong image assignment on multi thread
fix cache
Fix error not showing
remove unnecessary placeholder setting
fix stuff
revert
keep indicator animating at the beginning
show progress at the beginning if no cache
show network activity while downloading
progress block doesn't need to be in main queue
write image to disk. load from disk when none in cache before downloading.