request #7717 Remove dependencies between REST api and plugins

For now, only agiledashboard is taken in account. In addition, cardwall resources are processed only
if AD is activated.

Change-Id: I452476e6346a6c674c4d4a08895686c58d3c0ad2
Merge commit 'refs/changes/15/3415/5' of ssh://gerrit.tuleap.net:29418/tuleap into stable

* ssh://gerrit.tuleap.net:29418/tuleap:
  request #7717 Remove dependencies between REST api and plugins
This is Tuleap 7.8.99.31

Change-Id: I369754e3e1a3920e90b86ac0b179218b54c1679a