initial: learning switch example

example code for learning switch / hub
added as module into parent pom
added into distribution/base pom
handler + listener divided to atomic methods
initial flow written + sent to switch
bridge flows written to switch
storing covered mac-paths

Change-Id: I016055ed0920fb08c1923fa337c3e5b8880aba56
Signed-off-by: Michal Rehak <mirehak@cisco.com>
Signed-off-by: Tony Tkacik <ttkacik@cisco.com>