story #7571 - Add "Top backlog" option in "in milestone" filter

* add priority number in result
* DO NOT filter out unrelated artifacts at the moment

Change-Id: I43b534b6385b8e38c9e641d7eb48005f4c34bd14
story #7571 - Filter out unrelated artifacts

Change-Id: I1b378d40ce7fd33fec25d2e25ae6c7d2c2a6fa06
Story #7571 - Load and save in reports

Change-Id: Ia3423ae4472ee88352d0ca7a9a7cc59401342ad1
Story #7571 - Do not display "Top Backlog" option if it is not relevant

Change-Id: I108d9afe286435c6579bce219e6f2c59031eabf3
Merge commit 'refs/changes/60/3260/3' of ssh://gerrit.tuleap.net:29418/tuleap into stable

* ssh://gerrit.tuleap.net:29418/tuleap:
  Story #7571 - Do not display "Top Backlog" option if it is not relevant
  Story #7571 - Load and save in reports
  story #7571 - Filter out unrelated artifacts
  story #7571 - Add "Top backlog" option in "in milestone" filter

Conflicts:
	plugins/agiledashboard/include/autoload.php
This is Tuleap 7.7.99.36

Change-Id: I60744805b8c0a9a17bf535c3ac5d92d7c376be76