* app/edit_selection.c: when moving layers/masks freeze the undo
        after the first move to avoid that each and every small movements
        puts an undo on the stack. Significantly speeds up layer moves
        and especially the undo of a layer move.

        * app/gdisplay.h: correct rounding errors

        * app/gimpimage.c: correctly display floating selections in the
        composite_preview instead of ignoring them

        * app/channels_dialog.c
        * app/layers_dialog.c
        * app/lc_dialog.c: s/gtk_widget_draw/gtk_widget_queue_draw/

--Sven