autotier 1.0.4 (preview)

autotier 1.0.4

• Fix renaming directories containing files.
• Pass std::string instead of const char * to Metadata::update().
• Add global mutex lock to guard writing to database.
• Optional old_key argument for Metadata::update() to delete old DB entry
  atomically.
• Break out fuse methods into separate files and put in fuse_ops namespace.
• Use std::execution::par for sorting vector of files.

autotier 1.0.3

• Overhaul packaging using Docker.
• Rewrite popularity calculation method to be period length agnostic.
• Implement unordered map to store paths to open files, removing lsof dependency.