Re-parameterise contact interval as infectious period?

[joshwlambert]

I stumbled a bit on 'contact interval' (initially thought it was duration of contact for a specific contact). But then realised it's the temporal gap between contacts?

I think perhaps a more intuitive parameterisation would be to define an infectious period for the case, then distribute the times of infections among their contacts according to this distribution (like the implementation here), rather than relative to the time of interaction with the last contact (which I how I understand current approach works)?

Originally posted by @adamkucharski in #60 (comment)

[joshwlambert]

Implementing this now. One note, the contacts that are not infected are still sampled as being contacts within the infectious period. I will document this in the package so users are aware.