[DGD] DGD 1.6.4 & 1.5.8

[Felix A. Croes]

I have released two new versions of DGD, 1.6.4 and 1.5.8.

Version 1.5.8 reinstates the capability to restore snapshots from older
versions of DGD, all the way back to 1.1, without special tricks (other
than minor mudlib adaptions to API changes).  After recompiling all
objects in such a snapshot and creating a new one, version 1.6.4 is
capable of restoring the converted snapshot.

This will simplify upgrading to the latest version of DGD for any
persistent mud, which has previously been possible for muds following
the progress of DGD step by step, but more difficult for older ones
left behind.

Regards,
Felix Croes