- fixes #6

- increased version to 1.1

sigprops.xsd

 <?xml version="1.0" encoding="UTF-8"?>
 <xs:schema targetNamespace="http://slubarchiv.slub-dresden.de/sigprops1"
     xmlns="http://slubarchiv.slub-dresden.de/sigprops1" xmlns:xs="http://www.w3.org/2001/XMLSchema"
-    elementFormDefault="qualified" version="1.0">
+    elementFormDefault="qualified" version="1.1">
     <xs:annotation>
         <xs:documentation>XML files that are created based on this Schema describe exactly one
             digital object type. If your collection contains more than one object types, please create more
@@ -30,6 +30,11 @@
                                         XML.</xs:documentation>
                                 </xs:annotation>
                             </xs:element>
+                            <xs:element name="CreatorInstitution" type="xs:string" minOccurs="0" maxOccurs="1">
+                                <xs:annotation>
+                                    <xs:documentation>Institution to which the creator of this XML belongs.</xs:documentation>
+                                </xs:annotation>
+                            </xs:element>
                             <xs:element name="WorkflowName" type="xs:string" minOccurs="1"
                                 maxOccurs="1">
                                 <xs:annotation>