core: config parser extended with xavp_via_reply_params parameter

- allows to specify xavp name that is going to hold parameters to be
  added to the top via of replies

src/core/cfg.lex

@@ -304,6 +304,7 @@ LOGENGINETYPE	log_engine_type
 LOGENGINEDATA	log_engine_data
 XAVPVIAPARAMS	xavp_via_params
 XAVPVIAFIELDS	xavp_via_fields
+XAVPVIAREPLYPARAMS	xavp_via_reply_params
 LISTEN		listen
 ADVERTISE	advertise|ADVERTISE
 VIRTUAL		virtual
@@ -753,6 +754,7 @@ IMPORTFILE      "import_file"
 <INITIAL>{LOGENGINEDATA}	{ yylval.strval=yytext; return LOGENGINEDATA; }
 <INITIAL>{XAVPVIAPARAMS}	{ yylval.strval=yytext; return XAVPVIAPARAMS; }
 <INITIAL>{XAVPVIAFIELDS}	{ yylval.strval=yytext; return XAVPVIAFIELDS; }
+<INITIAL>{XAVPVIAREPLYPARAMS}	{ yylval.strval=yytext; return XAVPVIAREPLYPARAMS; }
 <INITIAL>{LISTEN}	{ count(); yylval.strval=yytext; return LISTEN; }
 <INITIAL>{ADVERTISE}	{ count(); yylval.strval=yytext; return ADVERTISE; }
 <INITIAL>{VIRTUAL}	{ count(); yylval.strval=yytext; return VIRTUAL; }

src/core/cfg.y

@@ -328,6 +328,7 @@ extern char *default_routename;
 %token LOGENGINEDATA
 %token XAVPVIAPARAMS
 %token XAVPVIAFIELDS
+%token XAVPVIAREPLYPARAMS
 %token LISTEN
 %token ADVERTISE
 %token VIRTUAL
@@ -890,6 +891,10 @@ assign_stm:
 			_ksr_xavp_via_fields.len=strlen($3);
 		}
 	| XAVPVIAFIELDS EQUAL error { yyerror("string value expected"); }
+	| XAVPVIAREPLYPARAMS EQUAL STRING { _ksr_xavp_via_reply_params.s=$3;
+			_ksr_xavp_via_reply_params.len=strlen($3);
+		}
+	| XAVPVIAREPLYPARAMS EQUAL error { yyerror("string value expected"); }
 	| DNS EQUAL NUMBER   { received_dns|= ($3)?DO_DNS:0; }
 	| DNS EQUAL error { yyerror("boolean value expected"); }
 	| REV_DNS EQUAL NUMBER { received_dns|= ($3)?DO_REV_DNS:0; }