[PD] list item picker widget - [declare] lib paths

[João Pais]

>> I'm not quite sure what the canonical declaration style is, -lib/-
>> path or -stdlib/-stdpath. I guess the former will work better for
>> Pd's own default setup.
> I should say this is true since 0.50 or so. Before that, -stdlib/-
> stdpath was the common thing to use.
What would be then the canonical now, no "-std"? I can change that 
easily in my patches, but would be good to have it confirmed.