Fixing #1648592 created a hard dependency on contrail-setup and contrail-vrouter-common packages.

[Krzysztof Klimonda]

After fixing #1648592 contrail-nodemgr for vRouter is failing to start if either one of the following is true:
1. /etc/contrail/debs_list.txt is missing.
2. contrail-vrouter-common package is not installed.

Both are caused by how contrail-version checks package versions. First issue is simple enough to fix -- in a short term, distribute debs_list.txt as part of contrail-utils package.

For the second one, the question is whether it's a packaging issue - I think it depends on how you look at it, contrail-vrouter-common doesn't provide anything important: it adds /usr/lib64/contrail/ to ld.so.conf -- that folder doesn't exist in R3.1 release anyway. I'd suggest that we check contrail-vrouter-agent version instead.