Provide interoperable MD5-based crypt() functions
'apache_md5_crypt()' provides a function compatible with Apache's '.htpasswd' files. This function is exported by default.
The 'unix_md5_crypt()' provides a crypt()-compatible interface to the rather new MD5-based crypt() function found in modern operating systems. It's based on the implementation found on FreeBSD 2.2.-RELEASE. This function is also exported by default.
For both functions, if a salt value is not supplied, a random salt will be generated, using the function random_md5_salt(). This function is not exported by default.