included gemstone-specific changes in Seaside-Session (copied from Seaside3.0)
added gemstone-specific changes from Seaside3.0 onto Seaside3.1
fixed json encoding
moved in the Zinc adaptor for Seaside3.1
Added the Zinc server (only works from gemtools, multithreaded server immediately throws out-of-mem in topaz)
Merge pull request #5 from jbrichau/master

Picked up changes from the Gemstone port of Seaside30 and merged them into Seaside31