Support freedesktop file association on Linux/Unix via the command line
arguments: `--register{-allusers}` `--unregister{-allusers}` as well
registration actions from the user preferences.
Once registered, the "Blender" application is available from launchers
and `*.blend` files are assoisated with the blender binary used for
registration.
The following operations are performed:
- Setup the desktop file.
- Setup the file association & make it default.
- Copy the icon.
- Setup the thumbnailer (`--register-allusers` only).
Notes:
- Registering/unregistering for all users manipulates files under
`/usr/local` and requires running Blender as root.
From the command line this can be done using `sudo`, e.g.
`sudo ./blender --register-allusers`.
From the GUI, the `pkexec` command is used.
- Recent versions of GNOME execute the thumbnailer in a restricted
environment (`bwrap`) requiring `blender-thumbnailer` to be copied
into `/usr/local/bin` (synlinks don't work).
So thumbnailing copies the binary rather than linking and only works
when registering for all users.
Ref !120283
