new option to auto-close varassign redirs; fixed some new parser error reporting issues

parser.h

@@ -49,6 +49,7 @@
 #define PST_COMMENT	0x100000	/* parsing a shell comment; used by aliases */
 #define PST_ENDALIAS	0x200000	/* just finished expanding and consuming an alias */
 #define PST_NOEXPAND	0x400000	/* don't expand anything in read_token_word; for command substitution */
+#define PST_NOERROR	0x800000	/* don't print error messages in yyerror */
 
 /* Definition of the delimiter stack.  Needed by parse.y and bashhist.c. */
 struct dstack {