src: clazy compiler warnings

get rid of most clazy warnings (https://github.com/KDE/clazy)
* range loop use refs
* qcolor ctor with ints
* missing Q_OBJECT macro
* use .constfirst instead of .first

enabled ccache for unix systems for fasterr recompiling
* if ccache is in path we use it now

src/lib_gui/qt/view/graphElements/QtGraphNodeAccess.h

@@ -8,6 +8,7 @@
 class QtGraphNodeAccess
 	: public QtGraphNode
 {
+	Q_OBJECT
 public:
 	QtGraphNodeAccess(AccessKind accessKind);
 	virtual ~QtGraphNodeAccess();