Adding the rest of the matrix scanning modes

- Not tested yet
- Added bug fixes for the scanCol and scanRow methods
- Merged in the powered versions of scanCol and scanRow
- Added the scanDual, but still needs heavy testing
- The scanDual uses twice the memory per key, so it can only scan half
  as much compared to the other scan modes

Scan/matrix/scan_loop.c

@@ -76,10 +76,17 @@ inline void scan_setup()
 inline uint8_t scan_loop()
 {
 	// Check count to see if the sample threshold may have been reached, otherwise collect more data
-	if ( scan_count++ < MAX_SAMPLES )
+	if ( scan_count < MAX_SAMPLES )
 	{
 		matrix_scan( (uint8_t*)matrix_pinout, KeyIndex_Array );
 
+		// scanDual requires 2 passes, and thus needs more memory per matrix_scan pass
+#if scanMode == scanDual
+		scan_count += 2;
+#else
+		scan_count++;
+#endif
+
 		// Signal Main Detection Loop to continue scanning
 		return 0;
 	}