Bug with updating attributes associated with self.native

[jmcgill298]

Attributes that are passed to init method are subsequently passed to another library for connection handling. These attributes are not currently being updated in the native attribute when they are updated on the object. These attributes need to be changed to descriptors and make use of a common setter method that updates the native attribute.

[FragmentedPacket]

@jmcgill298 Is this still required? I'm looking to contribute a bit more to this project.

[jmcgill298]

This is still needed. For drivers using netmiko, the update should be put into the netmiko_base branch into the netmiko base class.

[jmcgill298]

Also, nxos will be switched to use netmiko, so it can be excluded