Added

• Support for Read/Write of non-standard custom squashfs images:
  • LE_V4_0: (linux kernel) Little-Endian default official v4.0
  • BE_V4_0: Big-Endian v4.0
  • AVM_BE_V4_0: AVM Fritz!OS firmware support.
• FilesystemWriter: Builder pattern used when mutating an image. This includes multiple functions
  for the public API. Supporting both raw images and modification made to images that already exist.
• FilesytemCompressor: .compressor is now FilesystemCompressor,
  which holds the Id as well as options stored in the image as well as extra options only used when
  compressing when creating a new image.
• Add error InvalidCompressionOption
• Change default XZ compression level to 6
• Support custom XZ filters for FilesystemWriter
• Return (Superblock, bytes_written) for FilesystemWriter::write()
• Update deku to 0.16.0
• add: now reads file details to derive the details when the file is added the image
• add: --mtime, --uid, --gid and --permission to override file details derived from file
• unsquashfs: now correctly extracts ownership and permission details

Fixed

• ID now supports multiple IDs for GUI and UID in the table
• id_table is now properly a u64 pointer
• Data is now not copied when during the use of a FilesystemWriter you decide to change the compression used.
  Thanks @rbran

Changed

• Renamed SquashfsError to BackhandError