ProcessManager: Rename it to SystemMonitor

This is a more appropriate name now that it does a lot
more than just manage processes ^)

Applications/SystemMonitor/MemoryStatsWidget.h

@@ -0,0 +1,25 @@
+#pragma once
+
+#include <LibCore/CFile.h>
+#include <LibGUI/GWidget.h>
+
+class GLabel;
+class GraphWidget;
+
+class MemoryStatsWidget final : public GWidget {
+public:
+    MemoryStatsWidget(GraphWidget& graph, GWidget* parent);
+    virtual ~MemoryStatsWidget() override;
+
+    void refresh();
+
+private:
+    virtual void timer_event(CTimerEvent&) override;
+
+    GraphWidget& m_graph;
+    GLabel* m_user_physical_pages_label { nullptr };
+    GLabel* m_supervisor_physical_pages_label { nullptr };
+    GLabel* m_kmalloc_label { nullptr };
+    GLabel* m_kmalloc_count_label { nullptr };
+    CFile m_proc_memstat;
+};