add links from DataAttribute to Enumeration and ConstructedAttribute

...upelec.edf.riseclipse.iec61850.nsd.edit/plugin.properties

...c61850/nsd/provider/ConstructedAttributeItemProvider.java

...ipse/iec61850/nsd/provider/DataAttributeItemProvider.java

...clipse/iec61850/nsd/provider/EnumerationItemProvider.java

...ntralesupelec.edf.riseclipse.iec61850.nsd/model/nsd.ecore

...alesupelec.edf.riseclipse.iec61850.nsd/model/nsd.genmodel

...lec/edf/riseclipse/iec61850/nsd/ConstructedAttribute.java

...alesupelec/edf/riseclipse/iec61850/nsd/DataAttribute.java

...tralesupelec/edf/riseclipse/iec61850/nsd/Enumeration.java

...rc/fr/centralesupelec/edf/riseclipse/iec61850/nsd/NS.java

...ntralesupelec/edf/riseclipse/iec61850/nsd/NsdPackage.java

...iseclipse/iec61850/nsd/impl/ConstructedAttributeImpl.java

...c/edf/riseclipse/iec61850/nsd/impl/DataAttributeImpl.java

...lec/edf/riseclipse/iec61850/nsd/impl/EnumerationImpl.java

...tralesupelec/edf/riseclipse/iec61850/nsd/impl/NSImpl.java

...elec/edf/riseclipse/iec61850/nsd/impl/NsdPackageImpl.java