Added doctrine/collections dependency

Change-Id: Ie1d6fc3bb6ae2461361c5cbe767c029499e48deb
Added new types to represent better a support session

Change-Id: I724797051e4ffee37734b66f70dc4afb5ec11169
Fixed missing phpdoc

Change-Id: I393be1efabccea36e2b833e33fd72cb2244b5ba1