[HOW-TO] Install routed OpenVPN server in a VIMAGE portjail

After much frustration with the available documentation, I've finally managed to get OpenVPN installed and configured inside a VIMAGE portjail that allows me to access my FreeNAS box over the internet, so I figured I'd document the process here. A lot of the issues I had were due to slight differences in the systems that the guides were written for, resulting in slightly different paths or other minor differences that I banged my head against the wall over for far too long, so to be clear, this...

[HOW-TO] Install routed OpenVPN server in a VIMAGE portjail