Separate bootstrap from execution of data initialisation

Data initialisation leverage on tuleap API therefore it must have a fully
working Tuleap environment (TL;DR: include pre.php).

So we split it in 3 steps
api_test_bootstrap
-> initialise a fresh database
-> initialise base data on top of this DB
-> run actual tests

Change-Id: I34b235a6d6ce5ebe575f0f82080c5e8d64fb54c9
Planning tests

Comes with XML import init test

Change-Id: Ie37d18134663bfb17d113762907ee3726c70f17a
DRY on tests

Change-Id: Ib71cb508c11842307633287181595622839c15f4
Add tests on tracker routes

Change-Id: I58268c91001d405daba129331c9e432b1b829212
Merge remote-tracking branch 'gerrit/5442_rest_milestone' into tuleap-stable-master

* gerrit/5442_rest_milestone:
  Add tests on tracker routes
  DRY on tests
  Planning tests
  Separate bootstrap from execution of data initialisation

Change-Id: I9e64de32c722bf17777fdaa446cf8c4d7017e838
Tuleap 6.6.99.29

Change-Id: I33ac2febfeae6ead749fe2645cf93d05f562f8c6