Sync changes from upstream repository

Co-authored-by: Steve Baer <steve@mcneel.com>
Co-authored-by: Nathan Letwory <nathan@mcneel.com>
Co-authored-by: Dale Lear <dalelear@mcneel.com>

opennurbs_textiterator.h

@@ -546,6 +546,16 @@ public:
     {
       return m_text;
     }
+
+    const bool HasContent()
+    {
+      return m_has_content;
+    }
+
+    const void ClearHasContent()
+    {
+      m_has_content = false;
+    }
     
   private:
     bool                   m_has_content = false;