Vanilla OVS support implementation

Vanilla OVS support implementation

JIRA: VSPERF-57

This patch implements Vanilla OVS support.It contains:
* New IVswitch implementation: OvsVanilla,
* New configuration contants,
* New mandatory configuration variable: VSWITCH_VANILLA_PHY_PORT_NAMES
for Vanilla OVS has been added,
* Virtual ports are not yet implemented,
* Some kernel modules wrapping methods has been moved from dpdk.py to
tools.
* Fixed bug where ovsdb hasn't been killed at the end of test case run on
some platforms.

Change-Id: I21a0d84dbc4004aae564d5547387a2563f2d1e5b
Signed-off-by: Michal Weglicki <michalx.weglicki@intel.com>
Reviewed-by: Eugene Snider <Eugene.Snider@huawei.com>
Reviewed-by: Gurpreet Singh <gurpreet.singh@spirent.com>
Reviewed-by: Tv Rao <tv.rao@freescale.com>
Reviewed-by: Martin Klozik <martinx.klozik@intel.com>
Reviewed-by: Billy O Mahony <billy.o.mahony@intel.com>
Reviewed-by: Maryam Tahhan <maryam.tahhan@intel.com>