Add ClientSettings struct for client settings

Add "player" command line argument to choose the player backend.
Currently there are only for Android different players available.

client/client_settings.hpp

@@ -0,0 +1,57 @@
+/***
+    This file is part of snapcast
+    Copyright (C) 2014-2020  Johannes Pohl
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#ifndef CLIENT_SETTINGS_HPP
+#define CLIENT_SETTINGS_HPP
+
+#include <string>
+#include <vector>
+
+#include "player/pcm_device.hpp"
+
+
+struct ClientSettings
+{
+    struct ServerSettings
+    {
+        std::string host{""};
+        size_t port{1704};
+    };
+
+    struct PlayerSettings
+    {
+        std::string player_name{""};
+        int latency{0};
+        PcmDevice pcm_device;
+    };
+
+    struct LoggingSettings
+    {
+        bool debug{false};
+        std::string debug_logfile{""};
+    };
+
+    size_t instance{1};
+    std::string host_id;
+
+    ServerSettings server;
+    PlayerSettings player;
+    LoggingSettings logging;
+};
+
+#endif