BCrypt is regarded as a more secure alternative to hashing using message
digest algorithms, such as MD5 and SHA families [0, 1, 2]. Apart from
built-in salting it is adaptable to the increasing power of modern
processing units, which makes it more secure against brute-force cracking.
This commit makes all passwords hashed using BCrypt. The session tokens
remain generated using SHA1. Tests were updated, `rake test:units` and
`rake test:functionals` didn't report any regressions.
[0] http://bcrypt.sourceforge.net/
[1] http://en.wikipedia.org/w/index.php?title=Bcrypt&oldid=439692871
[2] eab1c72/README.md
