[Offline] Ignoring query string in static files

[bekliev]

Prerequisite

First you have to approve this PR #148 or #138 to serve cached files through service-worker.

About this PR

If you try to open static file (which has been cached), for example borat pic in the example app:

https://sapper-template.now.sh/great-success.png
It will open successfully!

But if you try to add some query strings, e.g.: ?foo=bar, then it will not work*:

https://sapper-template.now.sh/great-success.png?foo=bar
*if you approved this PR #148 or #138

So this PR solves above bug and ignores query strings.

[Rich-Harris]

I made this comment on sveltejs/hn.svelte.dev#3 but it's probably more applicable here:

Thank you. I'm not certain this is what we want — aren't query string parameters often used for cache busting purposes? (I realise that it's a hacky practice)

[bekliev]

You're right query parameters helping us to download again the file.
But in this case the file is not downloading at all - server's responding with 404 error - that's not correct in my opinion