This is a scattered commit, but it includes more unit test fixes, including...

This is a scattered commit, but it includes more unit test fixes, including Forwarding and the NotificationManager's interdependency issue the unit tests were having when being run together as a group. It also includes some typo repairs. The last major change is a bug fix in the LinkDiscoveryManager that fixes the long-time issue of LINK_ADDED and PORT_STATUS messages being inconsistent when a link is brought up. The issue was a race condition between the PORT_STATUS update timer to process the queues and the propagation of LLDP packets from one switch to another that cause the LINK_ADDED updates.