* Clarify which ping module to use
Ensure each of the ping modules link to each other
ping - Requires Python on remote-node
nxos_ping - Only on Cisco NXOS
ios_ping - Only on Cisco IOS
net_ping - For network devices
win_ping - only for Windows
* Refactor common network shared and platform specific code into package (part-1)
As per proposal #76 refactor common network shared and platform specific
code into sub-package.
https://github.com/ansible/proposals/issues/76
* ansible.module_utils.network.common - command shared functions
* ansible.module_utils.network.{{ platform }} - where platform is platform specific shared functions
* Fix review comments
* Fix review comments