Fix #313.

It's `warn()`, not `warning()`, so fix'em all.

korman/properties/modifiers/render.py

@@ -372,18 +372,18 @@ class PlasmaGrassShaderMod(PlasmaModifierProperties):
 
     def export(self, exporter, bo, so):
         if exporter.mgr.getVer() <= pvPots:
-            exporter.report.warning("Not supported on this version of Plasma", indent=3)
+            exporter.report.warn("Not supported on this version of Plasma", indent=3)
             return
         else:
             exporter.report.port("This will only function on MOUL and EOA", indent=3)
 
         materials = exporter.mesh.material.get_materials(bo)
         if not materials:
-            exporter.report.warning("No materials are associated with this object, no grass shader exported!",
+            exporter.report.warn("No materials are associated with this object, no grass shader exported!",
                                  indent=3)
             return
         elif len(materials) > 1:
-            exporter.report.warning("Ah, a multiple material grass shader, eh. You like living dangerously...",
+            exporter.report.warn("Ah, a multiple material grass shader, eh. You like living dangerously...",
                                  indent=3)
 
         for material in materials: