实现应用列表和SpkResource

SpkResource现有已知问题：首次使用不会完全进行所有任务。

inc/spkstretchlayout.h

@@ -0,0 +1,27 @@
+
+#pragma once
+
+#include <QtWidgets>
+#include <QVector>
+
+/**
+ * @brief SpkStretchLayout is meant solely for use with app list, where each layout item is
+ *        considered the same size.
+ */
+class SpkStretchLayout : public QLayout
+{
+  public:
+    SpkStretchLayout(QWidget *parent = nullptr);
+    ~SpkStretchLayout();
+
+    void addItem(QLayoutItem *item) override;
+    QSize sizeHint() const override;
+    QSize minimumSize() const override;
+    int count() const override;
+    QLayoutItem* itemAt(int) const override;
+    QLayoutItem* takeAt(int) override;
+    void setGeometry(const QRect &rect) override;
+
+  private:
+    QVector<QLayoutItem*> mItems;
+};