fixing some cppchecks

lib/Display/Bitmap.h

@@ -9,8 +9,8 @@ class OLEDDisplay;
 class Bitmap
 {
 public:
-	Bitmap(uint width, uint height);
-	Bitmap(OLEDDisplay * display);
+	explicit Bitmap(uint width, uint height);
+	explicit Bitmap(OLEDDisplay * display);
 	virtual ~Bitmap();
 
 	uint getWidth() const;

lib/TaskManager/TaskManager.h

@@ -71,7 +71,7 @@ private:
 class StatusFrame : public DisplayFrame
 {
 public:
-	StatusFrame(std::list<std::shared_ptr<Task>> tasks) : _tasks(tasks) {}
+	explicit StatusFrame(const std::list<std::shared_ptr<Task>> & tasks) : _tasks(tasks) {}
 	virtual ~StatusFrame() {}
 	void drawStatusPage(Bitmap & bitmap) override;