Capitalization, list model and room header work

- Standardized capitalization for variables and file names everywhere in
  QML and JS, get rid of mixed camelCase/snakeCase,
  use camelCase like everywhere in Qt

- ListModel items are now stored and returned as real QObjects with
  PyQt properties and signals.
  This makes dynamic property binding a lot easier and eliminates the need
  for many hacks.

- New update(), updateOrAppendWhere() methods and roles property
  for ListModel

- RoomHeader now properly updates when the room title or topic changes

- Add Backend.pdb(), to make it easier to start the debugger from QML

harmonyqml/components/sidePane/utils.js

@@ -0,0 +1,42 @@
+.import "../chat/utils.js" as ChatJS
+
+
+function getLastRoomEventText(roomId) {
+    var eventsModel = Backend.models.roomEvents.get(roomId)
+
+    for (var i = 0; i < eventsModel.count; i++) {
+        var ev = eventsModel.get(i)
+
+        if (ev.type !== "RoomMemberEvent") {
+            var found = true
+            break
+        }
+    }
+
+    if (! found) { return "" }
+
+    var name = Backend.getUserDisplayName(ev.dict.sender, false).result()
+    var undecryptable = ev.type === "OlmEvent" || ev.type === "MegolmEvent"
+
+    if (undecryptable || ev.type.startsWith("RoomMessage")) {
+        var color = ev.dict.sender === roomList.forUserId ?
+                    "darkblue" : "purple"
+
+        return "<font color='" +
+               color +
+               "'>" +
+               name +
+               ":</font> " +
+               (undecryptable ?
+                "<font color='darkred'>Undecryptable<font>" :
+                ev.dict.body)
+   } else {
+       return "<font color='" +
+              (undecryptable ? "darkred" : "#444") +
+              "'>" +
+              name +
+              " " +
+              ChatJS.getEventText(ev.type, ev.dict) +
+              "</font>"
+   }
+}