Procedure and tools to upgrade to gitolite3

Change-Id: Ie19a907de74b8cbf9ec549572d0e258c3538ccee
Merge commit 'refs/changes/53/1353/2' of ssh://gerrit.tuleap.net:29418/tuleap into tuleap-stable-master

* ssh://gerrit.tuleap.net:29418/tuleap:
  Procedure and tools to upgrade to gitolite3

Change-Id: I9770b31ec53f9eccfcbac442b6b979d92155a5fe
Tuleap 6.6.99.15

Change-Id: I7985df2b51ebfb14ef7f5d8fc456bbda8c749601