Added windows support

[jessevz]

solves #61 for windows.
Added windows support by:

• moving the init worker outside of the main function, the reason for that is that unlike with Linux, windows doesn't use fork where all resources are copied to the child. Instead windows uses spawn(), which requires the initworker function to be imported from a module-level scope — and that means it has to be pickleable, which local functions are not.
• Windows uses latin1 by default, I made it so that utf-8 encoding was used to have the same behavior as on Linux.

I have tested this code by running the tests on windows 11 from powershell and also on WSL with debian to check if this also still works on Linux. What I did notice is that Windows performs way worse than on Linux. It took windows 4:18 minutes to pass all tests vs 4,40 seconds on Linux. I assume this has something to do with how windows does multithreading.

[zyronix]

I have played around with this, I am bit worried by the code as it is indeed so slow under windows. Maybe you could find a solution for this?