lots more stuff

- proper gzip download for disk system (aka WNI reinventing the Content-Encoding: gzip wheel)
- send Last-Modified for static files
- send wtv-checksum for all disk system downloads
- other fixes

zefie_wtvp_minisrv/config.json

@@ -21,6 +21,7 @@
     "enable_gzip_compression": true,
     "pc_server_hidden_service": "http_pc",
     "pc_server_hidden_service_enabled": false,
+    "show_diskmap": false,
     "allow_guests": true
   },
   "services": {