Latest development build

Minor tweaks (#71)

* satisfy clippy, cleanup format strings and formatting

* build on macos-latest

* update workflow versions

v0.1.2

• Handle failed mounts better, with an appropriate message and error
  code.
• Revise exit codes: 0 means success, 1 means FS error, 2 means CLI
  error.
• --time flag for emitting timing information on STDERR.
• Basic startup/shutdown benchmarking, with microbenchmarks.
• Upgrade to fuser 0.9.1. Concomitant bugfixes turn off AutoUnmount.
• Improvements/bugfixes in regression tests.

ffs v0.1.1

• Extended attribute user.type manages metadata.
• Ignore macOS extended attribute files ._*.
• --pretty flag for JSON and TOML.
• Wrote INSTALL.md.
• Improved manpage.
• --new flag for starting from an empty filesystem.
• --munge flag for controlling renaming; revised renaming policy. Restore files whose names are munged.

ffs v0.1.0

Initial release.

Binaries are in ffs.platform.