NIC Upgrades to current version (5.1)

[mjang]

Is your feature request related to a problem? Please describe

From Brett Wolmarans:

I have read our upgrade documention on versions greater than 4.0.0. and it seems to be incomplete or maybe just overly brief can more detail be added so the user does not have to infer quite so much

[mjang]

cc @ADubhlaoich

[mjang]

Note: @ADubhlaoich says "I'll probably spin out upgrade instructions into their own doc like I did for NGF to keep the purpose of each document coherent:"