pkt_gen: STC - Imix Genome Support
This patch adds Imix-Genome support to STC.
1. Imix, of type genome, is included in traffic configuration.
2. The genome is converted to appropriated weights and pkt-sizes.
3. Throughput test is run with imix-configuration.
4. genome configuration is added to results.
5. Added Reporting of Average-Frame-Size - if IMIX is configured.
6. Updated genome comments
7. Clarified the reference to RFC 6985.
JIRA: VSPERF-521
Change-Id: I813efb66338ee1d1320a01ce5e0834180461120c
Signed-off-by: Sridhar K. N. Rao <sridhar.rao@spirent.com>