[filebrowser] part 2
[3rdparty] add CppSQLite
[filebrowser] add persistent file cache
[filebrowser] add drag upload suppport
update changelog to 20140922
[filebrowser] add ui tweaks
[filebrowser] disable right-button's double click
[filebrowser] add key-press event
[filebrowser] enlarge the sizes
[filebrowser] use folder.png for directory
[filebrowser] prompt password dialog when open a encrypted repo