Remove username attribute

wise-webapp/src/main/java/com/wisemapping/rest/model/RestMindmap.java

@@ -81,8 +81,8 @@ public class RestMindmap {
         return mindmap.getCreator().getEmail();
     }
 
-    public String getLastModifierUser() {
-        return mindmap.getLastModifierUser();
+    public Collaborator getLastModifierUser() {
+        return mindmap.getLastEditor();
     }
 
     public String getLastModificationTime() {

wise-webapp/src/main/java/com/wisemapping/rest/model/RestMindmapHistory.java

@@ -44,7 +44,7 @@ public class RestMindmapHistory {
     public RestMindmapHistory(@NotNull MindMapHistory history) {
         this.id = history.getId();
         this.creation = history.getCreationTime();
-        this.creator = history.getCreator();
+        this.creator = history.getEditor().getFullName();
     }
 
     public String getCreationTime() {

wise-webapp/src/main/java/com/wisemapping/rest/model/RestMindmapInfo.java

@@ -88,7 +88,8 @@ public class RestMindmapInfo {
     }
 
     public String getLastModifierUser() {
-        return mindmap.getLastModifierUser();
+        final User user = mindmap.getLastEditor();
+        return user != null ? user.getFullName() : "unknown";
     }
 
     public String getLastModificationTime() {

wise-webapp/src/main/java/com/wisemapping/rest/model/RestUser.java

@@ -66,14 +66,6 @@ public class RestUser {
 //        return user.isActive();
 //    }
 
-    public String getUsername() {
-        return user.getUsername();
-    }
-
-    public void setUsername(String username) {
-        user.setUsername(username);
-    }
-
     public long getId() {
         return user.getId();
     }