metrolyrics: Remove executable bit

It's not needed.
lua-factory: Add support for auto-split-threshold source prop

This is needed for some sources to avoir large queries being made.
lua-factory: Add support for source-tags source prop
radiofrance: Add Radio France source

https://bugzilla.gnome.org/show_bug.cgi?id=722820
lua-factory: Add debug and warning Lua bindings

Even if we can easily modify sources (most of the time), we want
developers to sprinkle this to aid with debugging.
lua-factory: Add dgettext() binding to Lua
euronews: Add streaming TV news from Euronews

https://bugzilla.gnome.org/show_bug.cgi?id=724415