Use "new style" OSXFUSE >=3.3.0 mount process?

[tv42]

https://github.com/osxfuse/osxfuse/releases/tag/osxfuse-3.3.0

This might help unite the linux & osx code paths, and bring sanity to osx mounting.
Perhaps delay just enough that we can hard depend on OSXFUSE >=3.3.0?

[tv42]

Upstream is 3.x only going forward, so this might be the right excuse to drop 2.x support: macfuse/macfuse#290

[tv42]

Heads up: the future of macOS support is in danger. If you care about FUSE on macOS, please encourage talented developers to pick up maintenance of the open source project. See #224

[tv42]

macOS support has been removed. If somebody wants to pick up maintaining an open source macOS FUSE, or wants to fund supporting the proprietary continuation of OSXFUSE, please get in touch.
#224