Import Oslo's common rootwrap to Neutron

Use the common oslo-incubator rootwrap rather than maintain a
specific fork within Neutron.

- Migrated DnsmasqFilter use in dhcp.filters to the new EnvFilter
- Changed environment passing in ip_lib's netns.execute so that
  it can be properly matched using IpNetNsExecFilter + EnvFilter.
  It now calls "ip netns exec ns env A=B C=D command" instead of
  "A=B C=D ip netns exec ns command". Adjusted tests accordingly.

All the other changes are coming directly from the Oslo "rootwrap"
module sync.

Notes:
- Neutron locates its rootwrap.conf in etc/ rather than in etc/neutron
- Neutron maintains a specific bin/quantum-rootwrap-xen-dom0 which
  requires additional config in rootwrap.conf

Both behaviors were preserved in this commit, but this may need to be
addressed in the future to simplify future oslo-rootwrap updates.

Implements bp: quantum-common-rootwrap

Change-Id: I02879942a9d1169a71aa4d684c1b9ec109a6de32
Ensure a name of packet filter is stored in NEC plugin

This patch fixes NEC Plugin to handle a name of packet filter and added
"name" column into PacketFilter table.

Fixes: bug #1198223
Change-Id: Ic191b2793653b41496922f2fa4be4f410d71dc64
Merge "Ensure a name of packet filter is stored in NEC plugin"
Merge "Import Oslo's common rootwrap to Neutron"
Add debian directory

Add debian directory so that Debian packages can be built from
the source.  The debian directory is the same as the one used by
Ubuntu Cloud Archive for Havana, intended to build packages to run
on Precise.  In this commit, Ubuntu Cloud Archive has not updated
its code to reflect the 'quantum'->'neutron' name change, so it
does not build.  This commit is meant to simply to initialize.

Signed-off-by: Ryu Ishimoto <ryu@midokura.com>