SFTP and FTP Upload Support

[Lyric4l]

I believe there should be an option for FTP and SFTP uploads similar to Imgur's upload feature. I have written a script for this and am using it, but it wouldn't be bad if this feature were directly integrated into the extension. Here is the script I wrote: https://github.com/Lyric4l/gnome-ss-uploader