Changelog:

• scrub status:
  • print percentage of progress
  • add size unit options
• fi usage: also print free space from statfs
• convert: copy full 64 bit timestamp from ext4 if avaialble
• check:
  • add ability to repair extent item generation
  • new option to remove leftovers from inode number cache (-o inode_cache)
• check for already running exclusive operation (balance, device add/...) when starting one
• preliminary json output support for 'device stats'
• fixes:
  • subvolume set-default: id 0 correctly falls back to tolpevel
  • receive: align internal buffer to allow fast CRC calculation
  • logical-resolve: distinguish -o subvol and bind mounts
• build: new dependency libmount
• other
  • doc fixes and updates
  • new tests
  • ci on gitlab temporarily disabled
  • debugging output enhancements