Add notion of procedural effects

[grofit]

This will allow for things like procedural items/equipment/spells etc.

The high level idea is to have an interface for the procedural template governing the groups of possible effects and ranges of potency.

Then another interface to define the outputted procedural values which can be used within the resulting thing.

Possibly some helpers around generating procedural things based off templates as well as possibly some thinking on procedural names which make use of localisation data.

[grofit]

The new additions to ScalingFunctions will hopefully assist in this task when it comes around to be done, as this will allow you to work out the min/max scales for certain item stats etc and then pass the random values through them to generate the actual output values.