folders init
folder render in middle column
remove folder event
close/open folders
remove folder
improve add folder icon
add feed  to right place wp1
drop to folder
drop on folder moved to list
add folder to right place
shift+click on folder should display unread only
when folder is deleted, delete its feeds as well
add _rename_ to folder context menu
replace set with save
smart import/export of folders
save max folder id
save max ids on smart export/import
folder unread/total count
extend arrow clickable area
add mark all as read to folder context menu