Fix request #5145: do not add user widgets for services not activated

Bonus: enable trackerv5 my artifacts

Change-Id: I7708173c0648e2820a70c8716aab8ebd65ca275b
request #6963 Incorrect error code REST API

Change-Id: I14711c4869a1afc213b31a2bbeba1573e0eed09f
request #6972 : bug fix- previously hidden fields are now visible and editable for tracker admins

Change-Id: I3dc19fed014739938a083132a18923b7797c9123
request #6903: Can submit a new artifact even if I doesn't have "can submit" right on all fields

Change-Id: Ie41c03b91ca19ffc1201d0ae8c04ccc33e4cac5d
Fix request #6987 deleted trackers are shown in the REST api /trackers/:id

Change-Id: Ie99f4ab5539c4276c719ac33a1ff544f06f4db71
Fix request #7049: Workflow:The option "must not be empty" does not work for the field attachements

Change-Id: Ia3fcd1b58a4733b7801c7161159de8e87bcd4371
Fix request #7058: Can't submit anymore an artifact if I do not have submit rights on all reuired fields

Change-Id: I907cd029f0a00a678d59e23b520f4f2137c3cd83