request #6780: Number of artifacts in ArtifactLink field is wrong

+ style the artifact link tab when it is fetched through ajax

Change-Id: I9e41c4d476774079b603ef4e0e8cc8e4774b9100
Merge commit 'refs/changes/68/2368/1' of ssh://gerrit.tuleap.net:29418/tuleap into tuleap-stable-master

* ssh://gerrit.tuleap.net:29418/tuleap:
  request #6780: Number of artifacts in ArtifactLink field is wrong

Change-Id: I3b63779f6713684a34d59ee05213e28d3bf6c3ce
Tuleap 6.12.99.90

Change-Id: I48425cf3936cef94ba4f7b7d00d2808533b8013f