Empty and Double Enumeration

[Mark Wielaard]

Hi,

Since I needed an EmptyEnumeration and a DoubleEnumeration (in ClassLoader
see next email) I added two classes to the gnu/java/util dir.
The DoubleEnumeration is adapted from the one in java/util.
The new version is a bit nicer for the garbage collector if
you have chained a lot of double enumerations and works correctly for
null values and/or enumerations without any values. The old version is still
in java/util but can be removed if people like the one in gnu.java.util more.

    * gnu/java/util/DoubleEnumeration.java: new class, adapted from
    java.util.DoubleEnumeration. Clears references earlier, handles null
    and/or empty enumerations better.
    * gnu/java/util/EmptyEnumeration.java: new class.

Cheers,

Mark