#122 Tolog parser does not allow string values

[Kal Ahmed]

The tolog parser does not allow a query such as:

select $TOPIC from topic-name($TOPIC, $NAME),
value-like ($NAME, "test") ?

It appears that the parser only allows predicate
parameters to be either a variable or a reference. The
parser should also allow a string value as a predicate
parameter.

The parser will probably also need to be changed to
allow strings in /= comparisons too.