Windows: consider allow use of all 108 bytes for Unix socket paths

[jstarks]

Windows does not require null termination for Unix socket paths--all 108 bytes can be used in the path string.

However, Windows does not document this behavior, so #249 chose not to rely on this and to require null termination, reducing the number of bytes available in the path by one.

Consider fixing this once Windows fixes their documentation.

See #249 (comment)