Merge branch V1.6_develop_505

->added some additional checks in IedServer_updateVisibleStringAttributeValue and similar values (LIB61850-504): added checks to avoid buffer underflow in IedServer_getFunctionalConstrainedData (LIB61850-505)
->removed empty line
->added length checks in object reference and component construction when installing the default values in the data model (LIB61850-505)

tools/model_generator_dotnet/Tools/ICDFiles/simpleIO_ltrk_tests.icd

@@ -31,6 +31,8 @@
       </ConnectedAP>
     </SubNetwork>
   </Communication>
+	2 simpleIO_Ltrk_tests.icd  simpleIO -apaccessPoint1 -out model -modelprefix MODEL
+		
 				<IED name="simpleIO">
     <Services>
       <DynAssociation/>