Store warzone structures in main zone database

Instead of storing strutures in /dat/warzone-x/volume-y.sl3 anymore, they are stored in the main database file created for the warzone in /dat/warzone-x/volume-x.sl3. Tables is created for each structure, with the prefix being structure_HASH_. The HASH is a string hashCode run through a bitwise AND with Integer.MAX_VALUE, to prevent negative values from showing.

This is a step on the road to storing everything in a single database for the warzone. My plan is to eventually store warzone configuration in the database as well. In the ideal setup, there would be a table for teams, structure definitions, loadouts, and materials. Sadly, for configuration, we would most likely have to store teamcfg & zonecfg rules in a key-value table, unless @taoneill or @grinning has another idea.

I still need to do testing to make sure everything is backward-compatible. This conversion happens properly for nimitz-format zones and zones in the process of converting from degaulle format. When messing around earlier, I found that .txt configurations were broken due to numbered teams. I need to take a look at that. Most likely it is due to WarzoneTxtMapper not being maintained. The loader will probably have to be modified to load the new volumes and teams properly.