[committed] migrate Savable Map classes

I would like to migrate the Savable Map classes which you can see at


to trunk.

These classes can be used to save any of the supported types of data to UserData without the user having to write any Savable implementation.  They can also be used to support fields of these types in jME classes in the future.

These classes have been in use by HottBJ users for a couple weeks now.

The more Savable types of UserData the merrier!

One of HottBJ's most important features is only possible because of that classes so plz do it…

Committed w/ revs 4542 and 4543.