No longer attempting to dispose of a possibly null NetworkSessionCollection
When the host has disconnected, the network session is disposed and the user is
allowed to retry the connection

|SOURCE|
[PerspectiveViewControl]
* Moved the disposal of the NetworkSessionCollection to the end of the
  ConnectToConsole method, which also checks if the NetworkSessionCollection is
  null before disposing of the Collection
* Added an event handler for when the remote session disconnects, informing the
  user that the connection has been severed abnormally (this is the only case
  considered so far) and allowing the user to retry until a connection is
  re-established