allow i18n
As discussed on IRC, here is how looks Patchage 1.0.0 on a French localised D.E.:
Some strings are automatically translated and others not, leading to a strange mix between French and English.
It'd be great if all the non-stock stuff could be translatable, and I'm wanting to provide a French translation for this.
PS: if I'm not wrong, guitarix is using gtk/glade too, and is translatable. See: