Fix changes requested (#101)

- Fix code formatting issues.
- Document `Presence`.
- Improve `Presence.__lt__()` performance by
  defining a dict outside the method.
- Make presence ball radius relative to uiScale
  and configurable from theme.

src/gui/Pages/Chat/RoomPane/MemberView/MemberDelegate.qml

@@ -43,26 +43,9 @@ HTile {
                 }
 
                 TitleRightInfoLabel {
+                    id: lastActiveAt
                     tile: member
                     visible: presenceTimer.running
-
-                    Timer {
-                        id: presenceTimer
-                        running:
-                            ! model.currently_active &&
-                            model.last_active_at > new Date(1)
-                        repeat: true
-                        interval:
-                            new Date() - model.last_active_at < 60000 ?
-                            10000 :
-                            60000
-                        triggeredOnStart: true
-                        onTriggered: parent.text = Qt.binding(() =>
-                            utils.formatRelativeTime(
-                                new Date() - model.last_active_at
-                            )
-                        )
-                    }
                 }
             }
 
@@ -84,6 +67,20 @@ HTile {
                         ""
                     )
             }
+
+            Timer {
+                id: presenceTimer
+                running:
+                    ! model.currently_active &&
+                    model.last_active_at > new Date(1)
+                repeat: true
+                interval:
+                    new Date() - model.last_active_at < 60000 ? 10000 : 60000
+                triggeredOnStart: true
+                onTriggered: lastActiveAt.text = Qt.binding(() =>
+                    utils.formatRelativeTime(new Date() - model.last_active_at)
+                )
+            }
         }
     }