* support for custom comparators in LIQ `order by` clauses via the
`using` keyword.
* `using` is mutually exclusive with `asc`/`desc` and accepts either
a *named function* or an *inline anonymous function*. The comparator
receives two values and returns true if the first should come before the
second.
* `nulls first`/ `nulls last` works independently of `using`.
* `using` is now a reserved keyword (`kw`; this cannot be avoided but
the chance to collide with user scripts is negligable),
* documentation updated + polished a little
Signed-off-by: Matouš Jan Fialka <mjf@mjf.cz>
Matouš Jan Fialka
01dd7c1db4