Changes

GH-5030: fix FedXDataset support for queries with FROM clauses

FedX supports interpret the Dataset being defined on the query: if it is
of type FedXDataset, the federation is reduced to the members defined by
FedXDataset#getEndpoints().

This is a nice means to evaluate a query on a subset of the federation
and is generally working fine.

When the query contains a FROM clause, however, the externally passed
Dataset is wrapped into a FallbackDataset (which internally keeps the
FedXDataset as primary one.

This change now inspects the FallbackDataset and unwraps it to reduce
the members. Note that for execution still the "FallbackDataset" is
used.
 (commit: 208459f)

GH-5033: fix pushing of limits for simple ASK queries in FedX

This change makes sure to push limits for simple ASK queries with a
single statement patterns into the query.

The optimization is the same as applied for simple SELECT queries with a
LIMIT.

Rational: if the limit is not pushed, the federation engine will first fetch all data for the statement pattern and only then locally check if there is at least one, i.e it will cause performance issues and memory pressure when there are many triples matching the statement pattern (for instance millions of persons).
 (commit: 099646a)

release 5.0.0

Signed-off-by: Håvard Ottestad <hmottestad@gmail.com>
 (commit: 8b31432)

next development iteration: 5.0.1-SNAPSHOT

Signed-off-by: Håvard Ottestad <hmottestad@gmail.com>
 (commit: 1b7a960)

set correct version

Signed-off-by: Håvard Ottestad <hmottestad@gmail.com>
 (commit: 70703fc)