Commit of the underlay/overlay mapping code
This is bringing code from rajreddy underlay repos, but because
of rebase problems, we are bringing this as a single commit
2 main components with this commit are
- snmp collector code
- topology calculation code
- ipfix receiver code

Adding 2 missing files from earlier commit..

Change-Id: If23b1c4d26c195791f388561736481a9ce6654ee
Merge "Commit of the underlay/overlay mapping code This is bringing code from rajreddy underlay repos, but because of rebase problems, we are bringing this as a single commit 2 main components with this commit are - snmp collector code - topology calculation code - ipfix receiver code"