for review: deep copy cleanup.

[Lee Naish]

Tyson Dowd <trd at cs.mu.OZ.AU> writes:

>Here's a cleanup of deep copy.  This should make it easier to add
>other functions that need to do similar things. 

Prompted by a brief discussion on the tram last night about doing a
binary dump of the HLDS in order to save information for declarative
debugging:

It would be nice to document what happens if the original version of the
data structure contains sharing.  With a (reasonably quick) look at the
code it seems like 1) its not documented and 2) nothing clever is done,
resulting in sharing being lost (ie, subterms get copied multiple times
rather than shared) - in the worst case this can lead to a exponential
increase in memory consumption.

Of course I could be wrong on both counts...

	lee