Jean Felder authored Sep 24, 2018 and Marinus Schraal committed Oct 02, 2018

Some Grilo plugins used by Music are written in lua (for example,
theaudiodb-coverart one). Flatpak default runtime does not provide lua
support, so these plugins are disabled.

Add Flathub shared modules as a git submodule. Add lua manifest file from
this repository to enable lua support in flatpak builds.
Enable lua support in grilo-plugins compilation.

Closes: #226