bug in highlight.js: function maj_highlight

[athenaxing]

trace_new = t.get_syntax_trace(changes.newTextLine).replace(/\r/g, '');

get_syntax_trace will return undefined sometime.

solution：
change the code

    // return identication that allow to know if revalidating only the text line won't make the syntax go mad
    EditArea.prototype.get_syntax_trace= function(text){
        if(this.settings["syntax"].length>0 && parent.editAreaLoader.syntax[this.settings["syntax"]]["syntax_trace_regexp"])
            return text.replace(parent.editAreaLoader.syntax[this.settings["syntax"]]["syntax_trace_regexp"], "$3");
    };

to

    // return identication that allow to know if revalidating only the text line won't make the syntax go mad
EditArea.prototype.get_syntax_trace= function(text){
    if(this.settings["syntax"].length>0 && parent.editAreaLoader.syntax[this.settings["syntax"]]["syntax_trace_regexp"])
        return text.replace(parent.editAreaLoader.syntax[this.settings["syntax"]]["syntax_trace_regexp"], "$3");
       return " ";
};