0.17.0

Major changes:

• Change many integer-based public API parameters to strongly-typed newtypes and bitflags.
  This breaking changes affects many of the methods on Filesystem
• Change Filesystem trait methods to use &self, and require mounted filesystems to be Send + Sync + 'static
• Improve typed error handling across request/reply APIs
• Replace Vec<MountOption> mount APIs with a structured Config API, including ACL option handling
• Feature flags abi-7-xx are now ignored and will be removed in 0.18, with compatibility checks moved to runtime behavior
• Remove the old ABI-specific feature-flag surface (abi-7-9 through abi-7-19, plus tooling/docs/examples references)
• Add support for multiple event loops per session, which can be enabled via Config::n_threads
• Add experimental async API (AsyncFilesystem)

Minor changes:

• Rename BackgroundSession::join to umount_and_join, returning io::Result<()> instead of panicking
• Add FUSE_DEV_IOC_CLONE support and improve passthrough descriptor handling (ReplyCreate, ReplyOpen, BackingId)
• Improve passthrough descriptor handling (ReplyCreate, ReplyOpen, BackingId)
• Add FileType conversion from std FileType
• Add option to explicitly choose libfuse2 or libfuse3, prefer libfuse3 by default
• Support building without libfuse on BSD
• Remove remaining osxfuse support and improve macfuse compatibility
• The path to the fusermount binary can be specified with the FUSERMOUNT_PATH environment variable
• allow_root or allow_other must be enabled when using auto_unmount
• Remove deprecated mount and spawn_mount -- use mount2 and spawn_mount2 instead
• Update and expand documentation

Internal changes:

• Improve Linux/BSD/macOS test coverage by migrating mount tests to fuser-tests and expanding CI
• Rework session lifecycle internals (handshake/session startup, destroy ordering, and unmount error propagation)