* removes unneeded supports_multiplexing var
* refactors terminal_prompts_re to terminal_stdout_re
* refactors terminal_errors_re to terminal_stderr_re
* updates network_cli unit test cases
This updates the network_cli connection plugin to attempt to automatically
determine the remote device os. The device network os discovery can
be overridden by setting the ansible_network_os value.
* adds new connection plugin `network_cli` which builds on paramiko
* adds new plugin `terminal` used for manipulating network_cli terminals
* adds new field to play_context `network_os` settable as ansible_network_os
This commit adds the plugins necesary to establish a persistent cli connection
to network devices of ssh. It builds on the paramiko connection plugin
to create a shell environment that will persistent through ansible-connection.
The `newtork_cli` plugin then uses the network_os in the instance of
PlayContext to load the appropriate network OS environment plugin for
handling opening and closing of shells as well as privilege escalation.
Trishna Guha
Peter Sprygada
John R Barker
Nathaniel Case