Codec for <a href="http://en.wikipedia.org/wiki/Crypt_(Unix)">Unix Crypt</a>-style encoding. While similar to Base64, it is not compatible with Base64. <p/> This implementation is based on encoding algorithms found in the Apache Portable Runtime library's <a href="http://svn.apache.org/viewvc/apr/apr/trunk/crypto/apr_md5.c?revision=HEAD&view=markup">apr_md5.c</a> implementation for its {@code crypt}-style support. The APR team in turn received inspiration for its encoding implementation based on FreeBSD 3.0's {@code /usr/src/lib/libcrypt/crypt.c} implementation. The accompanying license headers have been retained at the top of this source file. <p/> This file and all that it contains is ASL 2.0 compatible.