remove PVField::notImplemented

An unused waste of space in every instance...

src/factory/PVField.cpp

@@ -24,8 +24,7 @@ using std::string;
 namespace epics { namespace pvData {
 
 PVField::PVField(FieldConstPtr field)
-: notImplemented("not implemented"),
-  parent(NULL),field(field),
+: parent(NULL),field(field),
   fieldOffset(0), nextFieldOffset(0),
   immutable(false)
 {

src/pv/pvData.h

@@ -254,7 +254,6 @@ protected:
 private:
     static void computeOffset(const PVField *pvField);
     static void computeOffset(const PVField *pvField,std::size_t offset);
-    std::string notImplemented;
     std::string fieldName;
     PVStructure *parent;
     FieldConstPtr field;