Better Filesystem Capability Checks (e.g. volname & st_birthtime) #5

[undaunt]

As per @CoordSpace from x1ppy#5

When running freezetag mount on non-Mac filesystems, the current set of file attributes and fuse mount settings cause Runtime Errors with fuse such as fuse: unknown option "volname=Music-freezetag" and trigger the persistent process to instantly crash out.

This patch swaps out checks for OS(es) that don't support these features (e.g. if platform.system() != 'Windows') for checks that see if freezetag is running on the one OS variant that does support them: Darwin. This will allow linux (and maybe windows) users to use freezetag mount with filesystems that do not support that same filesystem feature set as MacOS.

So far this patch has been tested on the latest versions of Ubuntu Server and Debian and it clears the hurdles that prevented the new filesystem from being created, allowing well-behaved FLAC and MP3 files to work as expected.