Add options /milestones/:id/cardwall

Change-Id: I7b4a8a5dce48496753b60a7cd75132ede430d813
Merge "Add options /milestones/:id/cardwall" into 5648_cardwall_rest
Adding GET REST route for milestones/:id/cardwall

Change-Id: Iac38dd415f410e3376600596d14c60241bd80c09
Merge remote-tracking branch 'gerrit/5648_cardwall_rest' into tuleap-stable-master

* gerrit/5648_cardwall_rest:
  Adding GET REST route for milestones/:id/cardwall
  Add options /milestones/:id/cardwall

Change-Id: I980b0278c43b9d112f1d43595c898f22d618d987
Tuleap 6.8.99.4

Change-Id: I6044c821cd490705ab436247cf49372a8536e6ac