Bugfix release.

• [Bugfix] Crash or spinning beachball after upload #504
• [Bugfix] Active mode connections broken (FTP) #450
• [Bugfix] Removed graphical error messages for the sake of simplicity; displayed in log drawer instead #580
• [Bugfix] Hostname reachability check slow and blocking user interface #575
• [Bugfix] Fails to delete folders recursively in some cases #533
• [Bugfix] Unilingual builds broken #436
• [Bugfix] Cannot delete symbolic links #616