add Dropbox SDK
integrate Dropbox SDK and added simple browser
code cleanup
add network indicator
sort file listing
set title of navigationviewcontroller
simplify song import
add simple dropbox file import
toggle checkbox and save checked items
simplify sorting
enable import button when items selected
clear detail text for folders (fix "ghosting")
deselect row after tapped
remove unnecessary property
extract common subclass for importing files
rename Dropbox import ui class
finish rename
rename initWithPathString method
rename documentsDirectory method
add iTunes import ui class