Extend $datetime->elapsedTimeStr() to show "months" and "years"

[isellsoap]

Short description of the enhancement

Seen at https://processwire.com/talk/topic/21345-datetime-elapsedtimestr-not-showing-months-and-years/: I think it would make sense to extend $datetime->elapsedTimeStr() to also show months and years.

Current vs. suggested behavior

Currently $datetime->elapsedTimeStr() stops at "weeks", e.g. displaying "161 weeks", which is a bit weird. Instead, it should display "3 years, 4 months, …".

Why would the enhancement be useful to users?

For longer periods of time $datetime->elapsedTimeStr() doesn’t make much sense, because something like "254 weeks" isn’t something people are used to read or comprehend. Breaking that down into months and years would make this method a lot more useful.