JSZip v3.10+ breaks in some sandboxed browser environment because dependency setimmediate breaks

[edyhchan]

JSZip v3.10+ breaks in certain browser sandboxed environment such as userscript engine Tampermonkey because the new dependency in v3.10 setimmediate breaks in that case.
This is explained in Tampermonkey issue #1600 along with a workaround. Dependency setimmediate compares event.source === global but in sandboxed Tampermonkey this is not true.

Steps to reproduce:
Create a userscript in Tampermonkey with sandbox enabled by putting @grant to something other than none.
Use JSZip's generateAsync().
generateAsync() does no work and no error is thrown.

This is likely what people in issue #864 is experiencing.

Perhaps JSZip can use a different setImmediate shim or move away from using it altogether since it's currently non-standard.

[444171810]

For anyone experiencing this, try my solution here #864 (comment). Let me know if it works