HONEYCOMB-233: add support for mixing L2/L3 rules

HONEYCOMB-233: add support for mixing L2/L3 rules

In case of L2 interfaces, acls are translated into
a chain of classify tables and assigned as L2 table.

In case of L3 interfaces, acls are translated into
ip4 and ip6 chains (eth only rules go to
both chains, rest - depending on ip-version).

Limitations:
- it is not possible to define L3 rule without specifying ip-version
  (common header fields for IP4/IP6 have different offsets),
- eth rules on L3 interfaces are applied only to IP traffic
  (vpp classfier limitation).

Change-Id: I7ca2648cabad8c6e936cf71a51e06596a42891e8
Signed-off-by: Marek Gradzki <mgradzki@cisco.com>