v2.2

This version brings the whole bunch of the new features and fixes:

• Abort operation button / mtp-level transaction cancellation
• Drop zone for files (no drag, because X11 cannot "promise" files via drag-n-drop protocol )
• Device storage selection
• Warn about device being locked, asking user to unlock it.
• Prompt while overwriting files
• Recursive file downloading/uploading
• Fixed utf8 conversion for qt4
• More shortcuts
• Sort files by name
• Fixed many bugs and crashes