Recipe timings

[rathgar]

This is a complete rewrite of the previous attempt. This time using pure javascript to process ISO8601 durations. It's not perfect but means this feature will work in gh_pages environments as well as normal deployments.

Recipes will use ISO8601 formats as per previous PR but they will be able to use lowercase which should aid readability:

preptime: PT1h20m
cooktime: PT18m

The PT bit is needed as mentioned before to separate M (months) from M (minutes) although we could drop the initial P if that helps.

This does support translations and I've included english by default. There is currently no way (that I am aware of) that the app makes a language selection available to the js environment so it can't switch yet but the capability is there when it does.

Here's an exaggerated example:

and a more typical one:

also now works with components: