Provide a handler for the "About to serialize empty diffy version" warning during update.
Provide a handler for the "About to serialize empty diffy version" warning
during update.


git-svn-id: http://squeakvm.org/svn/squeak/branches/Cog@3641 fa1542d4-bde8-0310-ad64-8ed1123d492a

Former-commit-id: e21a124744158b015a9231fd015c0b9aaca5acc7
bencoman/pharo-vm,OpenSmalltalk/vm,timfel/squeakvm,OpenSmalltalk/vm,peteruhnak/pharo-vm,OpenSmalltalk/vm,timfel/squeakvm,bencoman/pharo-vm,peteruhnak/pharo-vm,OpenSmalltalk/vm,bencoman/pharo-vm,timfel/squeakvm,peteruhnak/pharo-vm,OpenSmalltalk/vm,bencoman/pharo-vm,OpenSmalltalk/vm,timfel/squeakvm,peteruhnak/pharo-vm,bencoman/pharo-vm,peteruhnak/pharo-vm,OpenSmalltalk/vm,peteruhnak/pharo-vm,OpenSmalltalk/vm,peteruhnak/pharo-vm,peteruhnak/pharo-vm,bencoman/pharo-vm,timfel/squeakvm,timfel/squeakvm,bencoman/pharo-vm,bencoman/pharo-vm,timfel/squeakvm,timfel/squeakvm,bencoman/pharo-vm