Add two new entries in the settings to choose different morphology dictionaries

[LAfricain]

Currently the only morph dic we can use is Parkard and Robinson in English. I translated this two dic in French, and it would be nice to have this features in the settings, as it is already possible to chose a different strong dic. This option is already in Bibletime.

[LAfricain]

@nwalkewicz do you think this issue is in your skill? I don't think it's too much work, but it's a pretty useful option.

[nwalkewicz]

I don't know yet (still pretty new to the codebase, C, and GTK), but I'd love to give it a shot! I'll write here again (with a mention) after the weekend when I have some more time to look into it.

[nwalkewicz]

@LAfricain Unfortunately I think this one is beyond me, for now at least; I've actually had trouble getting dictionaries to work at all in Xiphos.