Fix to allow indexed elements when mapping heirarchy elements

Fix has been made for below problem. DozerBuilder.java and FieldPropertyDescriptor.java has been modified. A week back I have raised the same issue. Issue# 164. Please let me know if changes are fine.

Problem when mapping below fields:
fieldA
fieldB[0].attribute1

When mapping fields as specified above and there is no set method available for fieldB. So i used is-accessible="true" for class b. When I do this Dozer does not recognize that fieldB is a list and hence it has to strip [0] when searching for the field name on the class.