Removed optional from ModuleClass.

SDT/schema4.0/etc/domain.rnc

@@ -120,7 +120,6 @@ ModuleClassesDef =
   element ModuleClasses {
     element ModuleClass {
       attribute name { xsd:Name },
-      attribute optional { xsd:boolean }?,
       attribute semanticURI { xsd:anyURI }?,
       attribute minOccurs { text }?,
       attribute maxOccurs { text }?,

SDT/schema4.0/src/domain.rng

@@ -344,11 +344,6 @@
 					<attribute name="name">
 						<data type="Name"/>
 					</attribute>
-					<optional>
-						<attribute name="optional">
-							<data type="boolean"/>
-						</attribute>
-					</optional>
 					<optional>
 						<attribute name="semanticURI">
 							<data type="anyURI"/>

SDT/schema4.0/src/domain.xsd

@@ -272,7 +272,6 @@
             <xs:element minOccurs="0" ref="Events"/>
           </xs:sequence>
           <xs:attribute name="name" use="required" type="xs:Name"/>
-          <xs:attribute name="optional" type="xs:boolean"/>
           <xs:attribute name="semanticURI" type="xs:anyURI"/>
           <xs:attribute name="minOccurs"/>
           <xs:attribute name="maxOccurs"/>

SDT/schema4.0/test/mseeb.xml

@@ -154,7 +154,7 @@
 -->
 
             <ModuleClasses>
-                <ModuleClass name="rootPowerOnOff" optional="true">
+                <ModuleClass name="rootPowerOnOff" minOccurs="0" maxOccurs="1">
                     <Doc>
                         The proprietry interface for turning all switches of the extension block on and off. 
                         The action "BooleanState:get" returns "true" when any of the sub-devices is in the state "on", otherwise it returns "false".