Multiple Qml app improvements

LibresapiLocalClient::request(...) return a meaningful value
ChatView.qml uses a TextField for message input
TrustedNodesView.qml improve aestetic
main.qml use stack based navigation and tool/menubar

retroshare-qml-app/src/qml/ChatView.qml

@@ -1,3 +1,21 @@
+/*
+ * RetroShare Android QML App
+ * Copyright (C) 2016-2017  Gioacchino Mazzurco <gio@eigenlab.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 import QtQuick 2.0
 import QtQuick.Controls 1.4
 import org.retroshare.qml_components.LibresapiLocalClient 1.0
@@ -43,16 +61,7 @@ Item
 		delegate: chatMessageDelegate
 	}
 
-	Rectangle
-	{
-		color: "green"
-		anchors.bottom: parent.bottom
-		anchors.left: parent.left
-		width: chatView.width - sendButton.width
-		height: Math.max(20, msgComposer.height)
-	}
-
-	TextEdit
+	TextField
 	{
 		id: msgComposer
 		anchors.bottom: parent.bottom