package/gerbera: new package

A free media server.
Stream your media to devices on your home network.

https://gerbera.io



Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
[Thomas:
 - fix S99gerbera to be compliant with the init script pattern
   that was recently put in place
 - add -l option in init script for logging
 - license code is GPL-2.0]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>