allow multi-line string property for text objects using cell arrays or char matrices * __axis_label__.m: Don't check type of txt argument. * __go_draw_axes__.m: Handle multi-line string property for text objects. * text.m: Likewise. * gl2ps-renderer.cc (glps_renderer::draw_text): Handle text::properties string property as octave_value object that can contain either a char array or cellstr object. * graphics.cc (axes::properties::update_xlabel_position, axes::properties::update_ylabel_position, axes::properties::update_zlabel_position, axes::properties::get_extent, text::properties::update_text_extent): Likewise. * graphics.h.in (text_label_property::do_set): Don't forget to set stored_type when value is a cell. (text::properties::get_string): Delete custom getter.

--- a/src/gl-render.cc
+++ b/src/gl-render.cc
@@ -2422,7 +2422,7 @@
 void
 opengl_renderer::draw_text (const text::properties& props)
 {
-  if (props.get_string ().empty ())
+  if (props.get_string ().is_empty ())
     return;
 
   const Matrix pos = xform.scale (props.get_data_position ());