Added support for ghosting matrices and code for elimination.

To use define GHOST in matrix.h, see example in Scan/CK3

Scan/MatrixARM/matrix_scan.h

@@ -139,6 +139,16 @@ typedef struct KeyState {
 	uint8_t         prevDecisionTime;
 } __attribute__((packed)) KeyState;
 
+// Ghost Element, after ghost detection/cancelation
+typedef struct KeyGhost {
+	KeyPosition     prev;
+	KeyPosition     cur;
+	KeyPosition     saved;  // state before ghosting
+} __attribute__((packed)) KeyGhost;
+
+//  utility
+inline uint8_t keyOn(/*KeyPosition*/uint8_t st)
+{	return (st == KeyState_Press || st == KeyState_Hold) ? 1 : 0;   }
 
 
 // ----- Functions -----