add migration to go from varchar -> char for uuid. Tested

on my machine, and works, but backing up before migrations
is always a good idea.

OpenSim/Data/MySQL/Resources/003_AssetStore.sql

@@ -0,0 +1,9 @@
+BEGIN;
+
+ALTER TABLE assets change id oldid varchar(36);
+ALTER TABLE assets add id char(36) not null default '00000000-0000-0000-0000-000000000000';
+UPDATE assets set id = oldid;
+ALTER TABLE assets drop oldid;
+ALTER TABLE assets add constraint primary key(id);
+
+COMMIT;