Added new Implementation for Bridge Discovery

Added a new way for bridge discovery
Added test for this way
Still failing!
Merge branch 'master' into features/TS
Merge branch 'master' into features/TS
Merge branch 'master' into features/TS
Merge branch 'master' into features/TS
Merge branch 'master' into features/TS
Refactoring of DiscoveryLink

Ready for the next iteration review the bridge discovery process
Fixed Loggin for DiscoveryLink
Added the BridgeTopology class

This class is designated to manage all bridge
topology operation
Clean LinkableNode

The LinkableNode class has been cleaned
to carry only information about the
single node
The BridgeTopology class will hold information
about bridge topology
Refactoring of topology class

Ready to implement BridgeDiscovery
Merge remote-tracking branch 'origin/master' into features/TS
Added useful fuctions and methods to performe bridge discovery
Merge branch 'features/TS' of github.com:OpenNMS/opennms into features/TS
Merge branch 'master' into features/TS
round 1 of stability fight
Added first logic for bridge link discovery

Added the bridge discovery for a special case
where the bridge forwarding table contains
mac addresses associated to bridge interfaces
Fixed all Tests for Linkd

The code is now refactored
still another improvement is
to use the BFT to get the
topology of the backbone links
Fixed Test for Linkd
initial work on D3layout implementation