expand on error testing in calc regression suite

Rename E_BROUND to E_BROUND_1 as per an earlier change
on the E_STRING formats.

    E_BROUND ==> E_BROUND_1

Improve the ciarify of calc regression suite (regress.cal) to mostly
use E_STRING errsym instead of numeric errnum values for error()
and errno() related tests.

value.c

@@ -1284,7 +1284,7 @@ broundvalue(VALUE *v1, VALUE *v2, VALUE *v3, VALUE *vres)
 	default:
 		if (v1->v_type <= 0)
 			return;
-		*vres = error_value(E_BROUND);
+		*vres = error_value(E_BROUND_1);
 		return;
 	}
 }