documents: Fix adding to/removing from folders with v3 of the API
documents: Fix adding to/removing from folders with v3 of the API

Helps: https://bugzilla.gnome.org/show_bug.cgi?id=593537

Distrotech/libgdata,pwithnall/libgdata,pwithnall/libgdata,Pecisk/libgdata-gtasks,Pecisk/libgdata,Distrotech/libgdata,GNOME/libgdata,Pecisk/libgdata,Pecisk/libgdata-gtasks,Pecisk/libgdata-gtasks,Pecisk/libgdata,Distrotech/libgdata