bugfix: Correct VM handling by integration tests

bugfix: Correct VM handling by integration tests

Patch with multi VM support has changed the way
how data are copied into the shared folder. Also
new support of GUEST_ options expansion requires
proper initialization with exact number of VMs
involved in the test.
Code of class specific to integration tests
was updated to initialize both GUEST_ options
and VM shared dir correctly.
Original values of all GUEST_ options are restored
after the testcase execution. So other TCs can
use original values for configuration expansion
to required number of VMs.

JIRA: VSPERF-361

Change-Id: Ic1149fbc73f73a66982bb64173b2217e55597200
Signed-off-by: Martin Klozik <martinx.klozik@intel.com>
Reviewed-by: Maryam Tahhan <maryam.tahhan@intel.com>
Reviewed-by: Al Morton <acmorton@att.com>
Reviewed-by: Christian Trautman <ctrautma@redhat.com>
Reviewed-by: Bill Michalowski <bmichalo@redhat.com>
Reviewed-by: Antonio Fischetti <antonio.fischetti@intel.com>