ugtrain: support multiple memory objects per class

In Chromium B.S.U. it is easy that we only have a single
HeroAircraft object. But in Warzone 2100 we have 47 Droid objects
which are created from the same malloc call upon campaign start.

So we need to support multiple memory addresses per dynamic memory
config in ugtrain. In order to reduce the output, we only print the
values in first memory object per class continuously.
ugtrain: add dumping of all mem. obj by '>' key

Now, we only need to press the '>' key and the memory objects of
all classes are dumped into files like this:
0_000.dump

This way we can analyze the memory contents better. Before the
underscore is the class ID and after it is the object ID within
the class. Existing files are overwritten. These are binary files
but it is possible to read and convert them with a HEX tool like
'xxd'.