Unify chat constants usage

common/string_util.cpp

@@ -123,6 +123,17 @@ std::vector<std::string> SplitString(const std::string &str, char delim) {
 	return ret;
 }
 
+static std::string implode(char *sep, std::vector<std::string> src)
+{
+	std::ostringstream output;
+	std::vector<std::string>::iterator src_iter;
+
+	for (src_iter = src.begin(); src_iter != src.end(); src_iter++)
+		output << *src_iter << sep;
+
+	return output.str();
+}
+
 std::string EscapeString(const std::string &s) {
 	std::string ret;