Add configurable connection timeout to netconf client.

Make connection timeout configurable. Previous behavior was having hardcoded connection timeout set to 1 minute.
Make NetconfConnectorModule more configurable, allow (and this is new default) to retry on connection failures forever.

Change-Id: Ia9280cff1b751a4e7318e1e0331175c960823dad
Signed-off-by: Tomas Olvecky <tolvecky@cisco.com>
Merge "Add configurable connection timeout to netconf client."