Fix bug in PVStructure equals() method

equals() was returning true if two structures had the same number of
fields, of equal type and equal value data, even if type IDs or field
names were not equal - correct this.

Author: dhickin

pvDataJava/src/org/epics/pvdata/factory/BasePVStructure.java

@@ -455,13 +455,16 @@ public boolean equals(Object obj) {
 		// TODO anything else?
 		if (obj instanceof PVStructure) {
 			PVStructure b = (PVStructure)obj;
+			if (!getStructure().equals(b.getStructure()))
+			    return false;
+
 			final PVField[] bfields = b.getPVFields(); 
 			if (bfields.length == pvFields.length)
 			{
 		        for (int i = 0; i < pvFields.length; i++)
 		        	if (!pvFields[i].equals(bfields[i]))
 		        		return false;
-		        
+
 		        return true;
 			}
 			else