integration: Support of integration testcases

integration: Support of integration testcases

Generic support for integration testcases with first
set of tests for vswitch testing.
New test option "TestSteps" has been introduced
to define test step by step directly in configuration
file.
In case that this concept will be accepted, there
are plenty of possibilities for future improvements.
For example:
* use it also for performance tests without explicit
call of validation methods
* introduce step macros for repetitive scenarios,
so new tests can be easily written
* further generalization, which would go beyond
usage of controllers and will operate directly
with vswitch, vnf and trafficgen objects

Change-Id: Ifad166c8ef9cfbda6694682fe6b3421e0e97bbf2
JIRA: VSPERF-212
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: Brian Castelli <brian.castelli@spirent.com>