- Users table model renamed to UsersTableModel- causes linker conflict

with class TableModel in accomodation plugin.
- Edit record dialog is now screen centered.
- Plugin tabs in application main window are now closable.

core/users/tablemodel.h

@@ -5,11 +5,11 @@
 #include "../data/core-data.h"
 #include "core-odb.hxx"
 
-class TableModel : public AutoTableModel<User>
+class UsersTableModel : public AutoTableModel<User>
 {
     Q_OBJECT
 public:
-    explicit TableModel(QObject *parent = NULL);
+    explicit UsersTableModel(QObject *parent = NULL);
 };
 
 #endif // TABLEMODEL_H