Set alias within prompt

To identify the other nodes without knowing the mac address based
hostname i have integrated a ```sh.shrc.local``` template that
overwrites ```PS1``` matching for the current shell and displaying the
currently set node alias instead of something like ```de8-9a-8f-bd-a1-48```.

It will be done on all nodes. And as we can define an alias on the admin node IMO it makes sense there too.