Add tracking of access times

See merge request !48

AdminXVII authored 5 years ago and Jeremy Soller committed 5 years ago

Add the atime field, which tracks the last access time. Only reads
update the atime.

**BREAKING CHANGE**: One less extent available per block, 4 more bytes
for node names.

Update path after frename

See merge request !46

Tests

See merge request redox-os/redoxfs!45

redoxfs: Add '--get-uuid' support

See merge request !44

With this, `redoxfs --get-uuid <disk>` prints out the UUID of the
provided redoxfs disk image.

This is needed especially for aarch64 kernels where the UUID of the boot
disk needs to be passed to the kernel by the bootloader. With this
extension to the mount command, the kernel build glue can query the
prepared redoxfs image for it's UUID.