Add support for qcow2 disks, adding the ability to choose qcow2 disk format when creating a VM from template. This is needed to provide more control over the format used to create the VM.
Moving from 4.0 alpha to 4.0 beta since 4.0 alpha has been already released and bug is not ON_QA.
Executed according to the following Polarion test run: https://polarion.engineering.redhat.com/polarion/#/project/RHEVM3/testrun?id=4_0_Storage_Ability_to_choose_qcow2_disk_format_when_creating_a_VM_from_%20template_run_19_07_2016 Moving to VERIFIED. Tested using: rhevm-4.0.1.1-0.1.el7ev.noarch vdsm-4.18.5.1-1.el7ev.x86_64