Add support for network-level administration

[frankiejarrett]

As pointed out in the support forum this plugin does not currently support managing user password expirations at the network-level. This is a must-have feature on multisite since users are shared across the entire network.

[BenHarris]

Is there any ETA on when this might be implemented? And do you have any thoughts on whether it should be implemented by detecting multi-site and only showing the config in the network? Or forking the plugin and producing a multi-site version with the "Network: True" plugin header?

[frankiejarrett]

@BenHarris I still want to implement this, but there's not an ETA.