Fix for single line comments ending in \

[Chris--A]

This is a fix for #956

Comments are still stripped, however, single line comments with a multi line directive are replaced with spaces while preserving the comment and multi line slash.

//A standard comment
unsigned char values[] = {
45, 12, 56, // A comment with a multi line pre-processor \
45, 13, 57,
45, 13, 58
};

/***
 * 
 * A fancy comment
 * 
 */

void setup() {/* An inline comment */}
void loop() {}

After pre-processing:

#line 1 "comment_error.ino"


#include "Arduino.h"
void setup();
void loop();
#line 3
unsigned char values[] = {
45, 12, 56,                                            //\
45, 13, 57,
45, 13, 58
};







void setup() {                       }
void loop() {}

[ffissore]

PdePreprocessor is a pit I don't want to dig further. #2729 fixes many of its issues but it's also outdated. I'll work on it next week. Thank you all the same