AthenaServices: A couple bug fixes related to metadata.

AttributeListKey should be a read handle, not a write handle! Avoid spurious WARNING about AttributeList during stop().

Also update reference files in AthenaPoolExampleAlgorithms to fix test failures in master.

This merge request affects 2 packages:

• Control/AthenaServices
• Database/AthenaPOOL/AthenaPoolExample/AthenaPoolExampleAlgorithms

Adding @ssnyder ,@mnowak as watchers

added Core Database master review-pending-level-1 labels

CI Result SUCCESS

	Athena	AthSimulation
externals
cmake
make
required tests
optional tests

Full details available at NICOS MR-20473-2019-01-21-11-17
Athena: number of compilation errors 0, warnings 0
AthSimulation: number of compilation errors 0, warnings 0
For experts only: Jenkins output [CI-MERGE-REQUEST 32459] (for remote access see the FAQ for MR reviewers)

Seems fine, approving.

Pavol [as L2 MR shifter]

added review-approved label and removed review-pending-level-1 label

merged

mentioned in commit fba95844

added sweep:ignore label