How to set up Wireless Networking in Ubuntu on the commandline

How to set up Wireless Networking in Ubuntu on the commandline  

Network Management under Ubuntu seems to be a complete pig's ear nowadays. I upgraded my laptop from 10.04LTS to 12.04LTS, and all manner of things b0rked :-( ...

I bravely proceeded to upgrade to 14.04LTS in the hope that it wall all magically get fixed... 

WRONG! :-/ 

Can *anyone* make head or tail of network-manager, avahi, all the *dm's and daemons / services / upstart processes / ??? now? 

I give up... 

Turned off the networking with the GUI, resorted to the good ol' commandline; see How to set up Wireless Networking in Ubuntu on the commandline for some details. 

It works! 

This has me in a(nother) minimalist mood.