add windows support - see (#602)

[ghost]

See (#602) for details. All credit goes to @JCapucho.

My changes are:

• rebasing against master
• making rodio the default background (platform-independent) & update windows-specific dependencies
• making the default config location based on directories without a fallback + a bit of logging

Feel free to change whatever! I've really only tested compiling this with msvc, but it works for me.

[ghost]

I wanted to clean this up a little - will reopen at a later date.

[Alexhuszagh]

@frankmoskal This doesn't seem to work: a great example is daemonize doesn't support Windows. There's a lot of imports that simply aren't supported on Windows, like use std::os::unix, and I'm not sure how to clean that up without a substantial rewrite.

Not sure how you got it to compile, but I'd be very happy if you could share. I'm using Rust 1.51.0 for x86_64-pc-windows-msvc and MSVC 2019 x86_64.

[Alexhuszagh]

Ok the dependencies that don't seem to work are as follows:

• syslog (a Unix-only system logger)
• dbus, dbus-tokio (optional, no big issue)
• alsa (optional, not used for our backend)
• daemonize

Other dependencies that fail after compilation include:

• xdg (Unix only, used for BaseDirectories)

And the function in get_shell_ffi src/utils.rs is currently not supported on Windows.

The main issue is daemonize, which seems to be unmaintained, Unix-specific, and may take some work to port over. syslog v5 supports Windows, while v4 and v4.0.1 only support Unix.

[Alexhuszagh]

I'm unsure of how we'd port daemonize, since the original relies on fcntl for the Python source, which is Unix-specific, just like the port.

[ghost]

@Alexhuszagh You'll actually want to look at frankmoskal-windows-dev - I moved things over to that branch after closing this MR to make things a bit easier on my end.

[Alexhuszagh]

@frankmoskal Ah my bad, I didn't see anything obvious in the branch list and just assumed it was on master.