A lot of improvements.

Fix laggish RoomListView when dragging.
Remove per-room timer and add timer in RoomForm.
Remove singleton module and use file as singleton.
Minor UI tweak in RoomListView.
Pass room to RoomListView via "currentRoom" delegate property and remove
RoomListForm-wide currentRoom.
Put menu files in a separate folder.
Show initial image in ImageStatus when avatar is not loaded.
Add about page.
Merge all setting pages into Setting.qml.
Add option to rearrange rooms by activity.
Add option to use RichText parser.
Add document url.

qml/menu/MessageContextMenu.qml

@@ -0,0 +1,38 @@
+import QtQuick 2.9
+import QtQuick.Controls 2.2
+
+Menu {
+    readonly property bool isFile: eventType === "video" || eventType === "audio" || eventType === "file" || eventType === "image"
+
+    id: messageContextMenu
+
+    MenuItem {
+        text: "Copy"
+        onTriggered: matriqueController.copyToClipboard(plainText)
+    }
+    MenuItem {
+        text: "Copy Source"
+        onTriggered: matriqueController.copyToClipboard(toolTip)
+    }
+    MenuItem {
+        visible: isFile
+        height: visible ? undefined : 0
+        text: "Open Externally"
+        onTriggered: delegateLoader.item.downloadAndOpen()
+    }
+    MenuItem {
+        visible: isFile
+        height: visible ? undefined : 0
+        text: "Save As"
+        onTriggered: delegateLoader.item.saveFileAs()
+    }
+    MenuItem {
+        visible: sentByMe
+        height: visible ? undefined : 0
+        text: "Redact"
+        onTriggered: currentRoom.redactEvent(eventId)
+    }
+
+    Component.onCompleted: popup()
+    onClosed: messageContextMenu.destroy()
+}