LLSD-14: Add tests from Simon's server-trunk changeset 3852648182db.

That changeset provides most of the changes previously checked in on this Jira
(viewer changeset 22b293aae639). Bring over the code he added to
llsd_new_tut.cpp as well.

indra/test/llsd_new_tut.cpp

@@ -742,6 +742,42 @@ namespace tut
 			LLSD w = v;
 			w = "nice day";
 		}
+
+		{
+			SDAllocationCheck check("shared values test for threaded work", 9);
+
+			//U32 start_llsd_count = LLSD::outstandingCount();
+
+			LLSD m = LLSD::emptyMap();
+
+			m["one"] = 1;
+			m["two"] = 2;
+			m["one_copy"] = m["one"];			// 3 (m, "one" and "two")
+
+			m["undef_one"] = LLSD();
+			m["undef_two"] = LLSD();
+			m["undef_one_copy"] = m["undef_one"];
+
+			{	// Ensure first_array gets freed to avoid counting it
+				LLSD first_array = LLSD::emptyArray();
+				first_array.append(1.0f);
+				first_array.append(2.0f);			
+				first_array.append(3.0f);			// 7
+
+				m["array"] = first_array;
+				m["array_clone"] = first_array;
+				m["array_copy"] = m["array"];		// 7
+			}
+
+			m["string_one"] = "string one value";
+			m["string_two"] = "string two value";
+			m["string_one_copy"] = m["string_one"];		// 9
+
+			//U32 llsd_object_count = LLSD::outstandingCount();
+			//std::cout << "Using " << (llsd_object_count - start_llsd_count) << " LLSD objects" << std::endl;
+
+			//m.dumpStats();
+		}
 	}
 
 	template<> template<>