Removes unnecessary Embrane module-level mocks

The embrane unit tests install a magicmock into
the system modules at the module level which
persists across all unit tests and isn't required.
This patch removes the unnecessary and limits the
life of the module mocks where they are necessary.

Partial-Bug: #1316401
Change-Id: Iaa38ee0c6821d46a6d78eefef39006df2c1c47e5
When l2-pop ON, clean stale ports in table0 br-tun

When l2-pop is turned ON, the tunnels towards a
specific node are created and torn down by other nodes,
based on availability of ports on that specific node in
specific networks. This generally reclaims the resources
used for such tunnels in all the nodes.

Under such conditions, in the current code (without this
fix), the cleaned up ports continue to be present in
rules of table0 of br-tun, resulting in flow explosion.

This fix adds cleanup-logic to remove such rules that
continue to use l2-pop cleaned up ports, from table0 of
br-tun.

Change-Id: I2639ff6432a13320adcadbcc0841319a99ce8c24
Closes-Bug: #1318261
Merge "Removes unnecessary Embrane module-level mocks"
Merge "When l2-pop ON, clean stale ports in table0 br-tun"