Windows support checklist

[whitequark]

First-class Windows support is within our reach. The remaining issues are:

• python-libusb1 needs to ship binary wheels.
• FX2 firmware needs to gain a workaround for Windows' inability to select configuration other than the first one. Or we should only use a single pipe everywhere else: [RFC] New basis of operation: Reliable Datagram Pipe #354
• Bitarray needs to be replaced with an in-tree, pure-Python implementation similar to bits from glasgow.support.bits. (Eliminate dependency on bitarray #179)
• Right now, yosys-abc cannot be quieted, and it's pretty annoying. YoWASP needs to gain the ability to run yosys-abc in a subprocess. This was implemented using in-process stdout/stderr redirection.
• Glasgow needs to be able to discover the native and YoWASP toolchain, and fall back to YoWASP if the native toolchain is incomplete. (target: locate and examine the FPGA build tools #353)

[whitequark]

Thanks to @mwkmwkmwk addressing #179 we only have a single item left until Windows support is exactly on par with every other supported platform! That one might take a while though.

I think this can be safely closed; I know a number of people use Glasgow on Windows with no issue and the minor performance regression compared to Linux that we'll need to eventually address architecturally isn't something most people will care about in first place.

🎉