Fix ECHOPAIR ambiguity

- Also patch up some warnings

Marlin/ConfigurationStore.cpp

         SERIAL_ECHOLNPGM("Z-Probe Offset (mm):");
         SERIAL_ECHO_START;
       }
-      SERIAL_ECHOPAIR("   M", CUSTOM_M_CODE_SET_Z_PROBE_OFFSET);
+      SERIAL_ECHOPAIR("   M", (unsigned long)CUSTOM_M_CODE_SET_Z_PROBE_OFFSET);
       SERIAL_ECHOPAIR(" Z", -zprobe_zoffset);
     #else
       if (!forReplay) {

Marlin/Marlin_main.cpp

       do_blocking_move_to( X_probe_location, Y_probe_location, Z_start_location); // Make sure we are at the probe location
 
       if (n_legs) {
-        double radius=0.0, theta=0.0, x_sweep, y_sweep;
+        double radius=0.0, theta=0.0;
         int l;
         int rotational_direction = (unsigned long) millis() & 0x0001;     // clockwise or counter clockwise
         radius = (unsigned long)millis() % (long)(X_MAX_LENGTH / 4);      // limit how far out to go

Marlin/vector_3.cpp

 	z = resultZ;
 }
 
-void vector_3::debug(char* title) {
+void vector_3::debug(const char title[]) {
 	SERIAL_PROTOCOL(title);
 	SERIAL_PROTOCOLPGM(" x: ");
 	SERIAL_PROTOCOL_F(x, 6);
   return new_matrix;
 }
 
-void matrix_3x3::debug(char* title) {
+void matrix_3x3::debug(const char title[]) {
   SERIAL_PROTOCOLLN(title);
   int count = 0;
   for(int i=0; i<3; i++) {

Marlin/vector_3.h

 	float get_length();
 	vector_3 get_normal();
 
-	void debug(char* title);
+	void debug(const char title[]);
 	
 	void apply_rotation(matrix_3x3 matrix);
 };
 
 	void set_to_identity();
 
-	void debug(char* title);
+	void debug(const char title[]);
 };