Changes
- support multi selection to manage downloads & uploads
- support overwrite files being shared from other Apps
- support sort files by name or by last modified time both in ascending and descending order
- fixed gallery browsing progress lost error after device rotated
- fixed searched result disappeared after device rotated
- fixed cannot open photos error in encrypted library
- fixed an error of ssl certificate validation
- fix account list became empty error when upgraded to 1.7.0+