Generate init_*.lua files

Rather than having .init.lua files sent statically by the server as they are right now, the client should genrate them based on the `mod_info.lua` file.

The `mod_info.lua` spec has already been extended to support this.

**Acceptance Criteria**
- Given the example featured mod 'FAF', a lua with with the same global `path` variable as executing the current `init_faf.lua` file should be generated.