FixBugs for iOS Safari

[mahdiyya]

Hi @wwilsman

Fix a crash that occurs only in iOS Safari when the page is restored from the Back-Forward cache. In that scenario, the value passed to serialize() is no longer a Date instance, so date.toLocaleDateString() throws:

TypeError: date.toLocaleDateString is not a function

Changes
Normalise the incoming value with new Date(date)

Reproduction steps

1. Open a page that uses Datepicker.js on iOS Safari.
2. Navigate away, then tap Back (BF-cache).
3. The picker fails to render, and the error above appears in the console.

Let me know if you'd like anything tweaked.

Thanks!
Diyah