Lazy loading

Idea

Framework for creating lazy loading data, and employ in some modules. There could also later be a generic Statgrab module lazily loading everything statgrab knows.

Implementation

Maybe a class that loads data on to_s to_i etc or maybe inspect calls, so using lazy fields is seamless in format strings and interpolation.

Benefits

We can then have less but more relevant modules, without loading what is not used. For example, CpuInfo and CpuUsage could merge into one single Cpu module.