Gold linker, CCache, Stats, LGTM

- Increases linker performance under Linux builds by using Gold linker, if available
- ccache is used if available
- removed statistic class (Stats.cpp) from project due to the missing result (sorry @Brindosch)
- add LGTM bandges for code analysis overview

Signed-off-by: Paulchen-Panther <Paulchen-Panter@protonmail.com>

include/hyperion/Grabber.h

@@ -84,12 +84,12 @@ public:
 	///
 	/// @brief get current resulting height of image (after crop)
 	///
-	virtual const int getImageWidth() { return _width; };
+	virtual int getImageWidth() { return _width; };
 
 	///
 	/// @brief get current resulting width of image (after crop)
 	///
-	virtual const int getImageHeight() { return _height; };
+	virtual int getImageHeight() { return _height; };
 
 	///
 	/// @brief Prevent the real capture implementation from capturing if disabled

include/hyperion/Hyperion.h

@@ -168,7 +168,7 @@ public:
 	/// @param[out] resultMsg  The feedback message
 	/// @return True on success else false
 	///
-	const bool saveEffect(const QJsonObject& obj, QString& resultMsg);
+	bool saveEffect(const QJsonObject& obj, QString& resultMsg);
 
 	///
 	/// @brief Delete an effect by name.
@@ -176,7 +176,7 @@ public:
 	/// @param[out] resultMsg   The message on error
 	/// @return True on success else false
 	///
-	const bool deleteEffect(const QString& effectName, QString& resultMsg);
+	bool deleteEffect(const QString& effectName, QString& resultMsg);
 
 	/// Get the list of available effects
 	/// @return The list of available effects
@@ -282,7 +282,7 @@ public slots:
 	/// @param  clearEffect  Should be true when NOT called from an effect
 	/// @return              True on success, false when priority is not found
 	///
-	const bool setInput(const int priority, const std::vector<ColorRgb>& ledColors, const int timeout_ms = -1, const bool& clearEffect = true);
+	bool setInput(const int priority, const std::vector<ColorRgb>& ledColors, const int timeout_ms = -1, const bool& clearEffect = true);
 
 	///
 	/// @brief   Update the current image of a priority (prev registered with registerInput())
@@ -293,14 +293,14 @@ public slots:
 	/// @param  clearEffect  Should be true when NOT called from an effect
 	/// @return              True on success, false when priority is not found
 	///
-	const bool setInputImage(const int priority, const Image<ColorRgb>& image, int64_t timeout_ms = -1, const bool& clearEffect = true);
+	bool setInputImage(const int priority, const Image<ColorRgb>& image, int64_t timeout_ms = -1, const bool& clearEffect = true);
 
 	///
 	/// @brief Set the given priority to inactive
 	/// @param priority  The priority
 	/// @return True on success false if not found
 	///
-	const bool setInputInactive(const quint8& priority);
+	bool setInputInactive(const quint8& priority);
 
 	///
 	/// Writes a single color to all the leds for the given time and priority
@@ -336,7 +336,7 @@ public slots:
 	/// @param[in] priority  The priority channel
 	/// @return              True on success else false (not found)
 	///
-	const bool clear(int priority);
+	bool clear(int priority);
 
 	///
 	/// @brief Clears all priority channels. This will switch the leds off until a new priority is written.

include/hyperion/ImageToLedsMap.h

@@ -57,8 +57,8 @@ namespace hyperion
 		///
 		unsigned height() const;
 
-		const unsigned horizontalBorder() const { return _horizontalBorder; };
-		const unsigned verticalBorder() const { return _verticalBorder; };
+		unsigned horizontalBorder() { return _horizontalBorder; };
+		unsigned verticalBorder() { return _verticalBorder; };
 
 		///
 		/// Determines the mean-color for each led using the mapping the image given
@@ -96,9 +96,9 @@ namespace hyperion
 
 			// Iterate each led and compute the mean
 			auto led = ledColors.begin();
-			for (auto ledColors = _colorsMap.begin(); ledColors != _colorsMap.end(); ++ledColors, ++led)
+			for (auto colors = _colorsMap.begin(); colors != _colorsMap.end(); ++colors, ++led)
 			{
-				const ColorRgb color = calcMeanColor(image, *ledColors);
+				const ColorRgb color = calcMeanColor(image, *colors);
 				*led = color;
 			}
 		}

include/hyperion/PriorityMuxer.h

@@ -151,7 +151,7 @@ public:
 	/// @param  timeout_ms  The new timeout (defaults to -1 endless)
 	/// @return             True on success, false when priority is not found
 	///
-	const bool setInput(const int priority, const std::vector<ColorRgb>& ledColors, int64_t timeout_ms = -1);
+	bool setInput(const int priority, const std::vector<ColorRgb>& ledColors, int64_t timeout_ms = -1);
 
 	///
 	/// @brief   Update the current image of a priority (prev registered with registerInput())
@@ -160,14 +160,14 @@ public:
 	/// @param  timeout_ms  The new timeout (defaults to -1 endless)
 	/// @return             True on success, false when priority is not found
 	///
-	const bool setInputImage(const int priority, const Image<ColorRgb>& image, int64_t timeout_ms = -1);
+	bool setInputImage(const int priority, const Image<ColorRgb>& image, int64_t timeout_ms = -1);
 
 	///
 	/// @brief Set the given priority to inactive
 	/// @param priority  The priority
 	/// @return True on success false if not found
 	///
-	const bool setInputInactive(const quint8& priority);
+	bool setInputInactive(const quint8& priority);
 
 	///
 	/// Clears the specified priority channel and update _currentPriority on success
@@ -175,7 +175,7 @@ public:
 	/// @param[in] priority  The priority of the channel to clear
 	/// @return              True if priority has been cleared else false (not found)
 	///
-	const bool clearInput(const uint8_t priority);
+	bool clearInput(const uint8_t priority);
 
 	///
 	/// Clears all priority channels

include/hyperion/SettingsManager.h

@@ -34,7 +34,7 @@ public:
 	/// @param correct If true will correct json against schema before save
 	/// @return        True on success else false
 	///
-	const bool saveSettings(QJsonObject config, const bool& correct = false);
+	bool saveSettings(QJsonObject config, const bool& correct = false);
 
 	///
 	/// @brief get a single setting json from config