Merge branch 'nikitakit_smoothbline' into nikitakit_ducks

Conflicts:
	synfig-core/po/fr.po
	synfig-core/po/ru.po
	synfig-studio/po/es.po
	synfig-studio/po/fr.po
	synfig-studio/po/ru.po
	synfig-studio/src/gtkmm/duckmatic.cpp

diff --cc synfig-studio/src/gtkmm/canvasview.cpp
index 594ad39,ee39ade..95fe556
--- 1/synfig-studio/src/gtkmm/canvasview.cpp
--- 2/synfig-studio/src/gtkmm/canvasview.cpp
+++ b/synfig-studio/src/gtkmm/canvasview.cpp
@@@ -2883,20 -2881,10 +2883,20 @@@ CanvasView::on_duck_changed(const synfi
  
        if (ValueNode_BLineCalcVertex::Handle bline_vertex = ValueNode_BLineCalcVertex::Handle::cast_dynamic(value_desc.get_value_node()))
        {
-               ValueNode_BLine::Handle bline = ValueNode_BLine::Handle::cast_dynamic(bline_vertex->get_link(bline_vertex->get_link_index_from_name("bline")));
+               ValueNode_BLine::Handle bline = ValueNode_BLine::Handle::cast_dynamic(bline_vertex->get_link("bline"));
                Real radius = 0.0;
 -              Real amount = synfig::find_closest_point((*bline)(get_time()), value, radius, bline->get_loop());
 -              return canvas_interface()->change_value(synfigapp::ValueDesc(bline_vertex,bline_vertex->get_link_index_from_name("amount")), amount);
 +              if (((*(bline_vertex->get_link("loop")))(get_time()).get(bool()))){
 +                      Real amount_old((*(bline_vertex->get_link("amount")))(get_time()).get(Real()));
 +                      Real amount_new = synfig::find_closest_point((*bline)(get_time()), value, radius, bline->get_loop());
 +                      Real difference = fmod( fmod(amount_new - amount_old, 1.0) + 1.0 , 1.0);
 +                                                      //fmod is called twice to avoid negative values
 +                      if (difference > 0.5) difference=difference-1.0;
 +                      return canvas_interface()->change_value(synfigapp::ValueDesc(bline_vertex,bline_vertex->get_link_index_from_name("amount")), amount_old+difference);
 +
 +              } else {
 +                      Real amount = synfig::find_closest_point((*bline)(get_time()), value, radius, bline->get_loop());
 +                      return canvas_interface()->change_value(synfigapp::ValueDesc(bline_vertex,bline_vertex->get_link_index_from_name("amount")), amount);
 +              }
        }
  
        if (ValueNode_BLineCalcTangent::Handle bline_tangent = ValueNode_BLineCalcTangent::Handle::cast_dynamic(value_desc.get_value_node()))