The `ns-reserved-directive` production consumes comments

[Thom1729]

Because ns-directive-parameter is defined as simply ns-char+, it will happily consume comments at the end of the line. E.g, in:

%FOO bar # baz

The ns-reserved-directive production will match all of FOO bar # baz. This is probably not the intent.

The practical implications of this are almost nil, since the parsing process should discard both comments and (with a warning) reserved directives. But it could also be easily fixed by redefining ns-directive-parameter to [ lookahead ≠ '#' ] ns-char+.