DATAMONGO-1449 - Switched to foreach loop in collection handling of MappingMongoConverter.

This should result in minor to moderate performance improvement for iteration on Collections/Arrays during DBObject to object mapping.

Original pull request: #368.

Author: herotheday

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/convert/MappingMongoConverter.java

@@ -901,9 +901,7 @@ private Object readCollectionOrArray(TypeInformation<?> targetType, BasicDBList
 		Collection<Object> items = targetType.getType().isArray() ? new ArrayList<Object>()
 				: CollectionFactory.createCollection(collectionType, rawComponentType, sourceValue.size());
 
-		for (int i = 0; i < sourceValue.size(); i++) {
-
-			Object dbObjItem = sourceValue.get(i);
+		for (Object dbObjItem : sourceValue) {
 
 			if (dbObjItem instanceof DBRef) {
 				items.add(DBRef.class.equals(rawComponentType) ? dbObjItem