Fix material convertsion and units detection.

zaaReloaded2/Thesaurus/Parameters.cs

@@ -69,16 +69,23 @@ namespace zaaReloaded2.Thesaurus
         /// <param name="laurisName">Lauris item name to look up.</param>
         /// <returns><see cref="zaaReloaded2.LabModel.Material"/> enum; if no material is
         /// found in the dictionary, the default material "S" (serum) is returned.</returns>
-        public Material GetMaterial(string laurisName)
+        public Material GetMaterial(string laurisName, Material def)
         {
             string textValue = LookUpValue(laurisName, 2);
-            try
+            if (String.IsNullOrEmpty(textValue))
             {
-                return MaterialFactory.FromAbbreviation(textValue);
+                return def;
             }
-            catch
+            else
             {
-                return Material.B;
+                try
+                {
+                    return MaterialFactory.FromAbbreviation(textValue);
+                }
+                catch
+                {
+                    return Material.B;
+                }
             }
         }