remove dead code

these RPC calls are probably a relict of first tries,
they are not exhaustive in their area are nor were ever used,
maybe not even working.
if we decide to go that way at some point anyways much more is needed :)

src/main/java/com/b44t/messenger/rpc/Rpc.java

@@ -79,23 +79,6 @@ public JsonElement getResult(String method, Object... params) throws RpcExceptio
         }
     }
 
-    public int addAccount() throws RpcException {
-        return gson.fromJson(getResult("add_account"), int.class);
-    }
-
-    public void startIO() throws RpcException {
-        getResult("start_io_for_all_accounts");
-    }
-
-    public void stopIO() throws RpcException {
-        getResult("stop_io_for_all_accounts");
-    }
-
-    public Map<String, String> getSystemInfo() throws RpcException {
-        TypeToken<Map<String, String>> mapType = new TypeToken<Map<String, String>>(){};
-        return gson.fromJson(getResult("get_system_info"), mapType.getType());
-    }
-
     public List<VcardContact> parseVcard(String path) throws RpcException {
         TypeToken<List<VcardContact>> listType = new TypeToken<List<VcardContact>>(){};
         return gson.fromJson(getResult("parse_vcard", path), listType.getType());