rewrite wtv-disk system

- move wtv-update to wtv-disk
- allow accessing wtv-disk:/sync?group=&diskmap=
- rewrite Download List generation to be more proper
- only send files if diskmap has changed
- allow force redownload with &force=true

zefie_wtvp_minisrv/config.json

@@ -72,7 +72,7 @@
       "port": 1630,
       "connections": 3
     },
-    "wtv-update": {
+    "wtv-disk": {
       "port": 1635,
       "connections": 3
     },