Fix processing of the args option

[schlagert]

Merging the latest PR broke passing of arguments to commands. This PR will fix this issue. It also preserves the replacement placeholder values per request. Additionally, placeholders can now also be used in global commands.

The previous approach was prone to cause race conditions on heavily loaded proxies due to using shared memory for the replaced arguments which has also been addressed.

[PascaleBeier]

Thanks a lot @schlagert, I was debugging this for a while. There really is a regression introduced in the last PR. Time for pinning my go modules.

[schlagert]

Is there anything we can do to get this PR approved/merged? I think the current state of master is pretty much broken.

[polarathene]

@abiosoft friendly ping

[abiosoft]

Thanks @schlagert for the fix, and everyone else for your patience.