Deserialize

Removed serialisation of trade codes and bases.  I think I can see why you did it that way to begin with - as you had no need to compare systems, it was easier than creating the tables - with only a name - and join tables...  

For the same reason I haven't removed the serialisation of "contraband" and "links". Not exactly sure what the best approach is for those.  Could also consider creating tables for the other items that have hashmaps in the systems table, but that's not really important right now