Compare items ID, not paths which creates duplicates

This happened when selecting radio discovery, for instance.
Probably also fixes #7516.

(so that channel reordering works)

Due to instability and leaks in libproxy, VLC now uses the executable
binary from libproxy-tools instead directly calling the functions.

To 4.0, 2.0 and 1.0

There should be no functionnal change here

Cross has a meaning for closing a menu, window.
Quit action closes everything (quits application).

- Fixes detection when spidf is available again, and resumes playing in spdif mode
  if this was selected before
- Fixes audio device list rebuilt if no audio is playing

refs #8286

Removes locale fix and conditionally builds fingerprinter.

Shortest ones are the best.