Allow to run unit tests in docker containers

+ Fix somes tests that were broken
How to run:
make tests_php51
make tests_php53
make tests_phpunit

Change-Id: I0ad38ab31ab1ea09a1edef4968121c07d733ce3c
Merge commit 'refs/changes/93/2893/2' of ssh://gerrit.tuleap.net:29418/tuleap into HEAD

* ssh://gerrit.tuleap.net:29418/tuleap:
  Allow to run unit tests in docker containers

Change-Id: Ifd01d964a5ed17106388e1b82f4c8c85792b15f9
This is Tuleap 7.3.99.61

Change-Id: I79b052f4f3b2302be71e98e9b0fc4f77775c428f