implement set videomode via json api (#457)

* implement set videomode via json api

* refactor grabbers:
- new base class
- move shared code to base class

* fix osx

* rework all cmakelist files with auto file collection. except leddevices (need further restructuring)

* store current video and grabbing mode

* add json stuff

* remove grabbingmode - we do not want to expose it

include/hyperion/Grabber.h

@@ -0,0 +1,53 @@
+#pragma once
+
+#include <QObject>
+#include <cstdint>
+
+#include <utils/Image.h>
+#include <utils/VideoMode.h>
+#include <utils/GrabbingMode.h>
+#include <utils/ImageResampler.h>
+#include <utils/Logger.h>
+
+
+class Grabber : public QObject
+{
+	Q_OBJECT
+
+public:
+	Grabber(QString grabberName, int width=0, int height=0, int cropLeft=0, int cropRight=0, int cropTop=0, int cropBottom=0);
+	~Grabber();
+	
+	///
+	/// Set the video mode (2D/3D)
+	/// @param[in] mode The new video mode
+	///
+	void setVideoMode(VideoMode mode);
+
+	/// gets resulting height of image
+	const int getImageWidth() { return _width; };
+
+	/// gets resulting width of image
+	const int getImageHeight() { return _height; };
+
+
+protected:
+	ImageResampler _imageResampler;
+
+	/// the selected VideoMode
+	VideoMode    _videoMode;
+
+	/// With of the captured snapshot [pixels]
+	int _width;
+	
+	/// Height of the captured snapshot [pixels]
+	int _height;
+
+	// number of pixels to crop after capturing
+	int _cropLeft, _cropRight, _cropTop, _cropBottom;
+
+
+	/// logger instance
+	Logger * _log;
+
+};