General: * Use Nepomuk describeResource and storeResource to send somehow an additional trig or rdf file. * Investigate if channels are closed channels when transfer ends/fails * Save metadata about sender and receiver * Send multiple files in a tarball and extract them on the other side * Send single files compressed to save bandwidth and extract on the other side Incoming file transfers * Close window if file transfer is cancelled * Ensure that when the file transfer fails or is cancelled the empty file is deleted and the .part file is left Outgoing file transfers