Fixed problem of indexOf in OObjectEnumLazyList

included test-cases:

containsTest()
indexOfTest()
lastIndexTest()
refactored methods in OObjectEnumLazyList

contains(Object o)
indexOf(Object o)
lastIndexOf(Object o)

All methods are including the same problem. There are two lists:
List\<Object> and ArrayList\<TYPE>. List\<Object> contains String values
and is equals to the String values in the database. The Strings
represent the names of the enum-values. The ArrayList\<TYPE> contains the
real enum-values, but these values are only loaded when the method
get(int index) will be used, otherwise the list only contains
null-values. So indexOf and contains doesn't work with this list.
So, if Object is a valid enum for this list, the name of this enum-value
will be used to use contains/indexOf of the List list.