pefs status report 5

[Gleb Kurtsou]

I've commited encryption support using rc4 last week. Trying to switch
to XTS-AES I came across Salsa20 stream cypher. I'm going to use if for
encryption as it allows encryption/decryption at arbitrary offsets, fast
and supports tweaks (additional key material).  Salsa20 sources need
some tweaking to support stream seeking. I'm working on it.  There is
also a bigger overhaul going on in my local repository: using Salsa20
allows to completely get rid of block alignment requirement in
read/write operations and I'm working on adding transparent mode of
operation (it's just like read-only nullfs, but necessary to correctly
handle mount root directory, lost+found and filesystem snapshots). It's
too unstable at the moment, so I'm planning to finish it and commit by
the end of the week.