Adds ConntrackCreate & ConntrackUpdate

[aaaaaaaalex]

• Also refactored setUpNetlinkTestWithKModule in test infrastructure, to reduce redundant NS's created and redundant checks made.

• Add conntrack protoinfo TCP support + groundwork for other protocols.

  • Will parse TCP protoinfo name+state when reading from kernel.
  • Will just parse other protocol's names and skip the rest.
  • Will only write TCP protoinfo name+state back to kernel, other protocol's groundwork is laid down.

• Tests to cover the above.

[fasaxc]

PR for #918

[aboch]

LGTM

@aaaaaaaalex please resolve the conflicts

[aaaaaaaalex]

@aboch done, thanks