app/testpmd: add ixgbe VF management
add test for set vf vlan anti spoof
add test for set vf mac anti spoof
add test for set vf vlan stripq
add test for set vf vlan insert
add test for set tx loopback
add test for set all queues drop enable bit
add test for set vf split drop enable bit
add test for set vf mac address
add new APIs to testpmd help command.
add new APIs to the testpmd guide
Modify Makefile, add library rte_pmd_ixgbe to _LDLIBS-y.
Signed-off-by: Bernard Iremonger <bernard.iremonger@intel.com>