CNotifier: Turn into a CObject and Use the event queue to deliver events

This way, CNotifier can mutate state to its little heart's content
without destroying the world when the global CNotifier hash changes
during delivery.

Libraries/LibCore/CEvent.h

@@ -13,6 +13,8 @@ public:
         Invalid = 0,
         Quit,
         Timer,
+        NotifierRead,
+        NotifierWrite,
         DeferredDestroy,
         DeferredInvoke,
         ChildAdded,
@@ -62,6 +64,36 @@ private:
     int m_timer_id;
 };
 
+class CNotifierReadEvent final : public CEvent {
+public:
+    explicit CNotifierReadEvent(int fd)
+        : CEvent(CEvent::NotifierRead)
+        , m_fd(fd)
+    {
+    }
+    ~CNotifierReadEvent() {}
+
+    int fd() const { return m_fd; }
+
+private:
+    int m_fd;
+};
+
+class CNotifierWriteEvent final : public CEvent {
+public:
+    explicit CNotifierWriteEvent(int fd)
+        : CEvent(CEvent::NotifierWrite)
+        , m_fd(fd)
+    {
+    }
+    ~CNotifierWriteEvent() {}
+
+    int fd() const { return m_fd; }
+
+private:
+    int m_fd;
+};
+
 class CChildEvent final : public CEvent {
 public:
     CChildEvent(Type, CObject& child);