Add a new function into Common to compare two XML files
3 new test case to check the flow are pushed to the switch correctly
Putting back the Variables i deleted last change.

Change-Id: I968ed7050a48595dfcd8a1b7bacee21dc39ebf61
Signed-off-by: Christopher O'Shea <christopher.o.shea@ericsson.com>
(cherry picked from commit 164c6eb4507edb225cc25211f835eab04a90997d)

Change-Id: Iaf7b2f4690998121b4d0851147ad0ce8031ff5f6
Signed-off-by: Luis Gomez <ecelgp@gmail.com>