Perform Microsoft NTLM and Basic User Authentication

 The purpose of this module is to perform a user authentication via Microsoft's
 NTLM protocol. This protocol is supported by all versions of the Internet
 Explorer and is mainly useful for intranets. Depending on your preferences
 setting IE will supply your windows logon credentials to the web server
 when the server asks for NTLM authentication. This saves the user to type in
 his/her password again.
 .
 The NTLM protocol performs a challenge/response to exchange a random number
 (nonce) and get back a md4 hash, which is built from the user's password
 and the nonce. This makes sure that no password goes over the wire in plain
 text.
 .
 The main advantage of the Perl implementation is, that it can be easily
 extended to verify the user/password against other sources than a windows
 domain controller.
 .
 The default implementation is to go to the domain controller for the given
 domain and verify the user. If you want to verify the user against another
 source, you can inherit from Apache2::AuthenNTLM and override it's methods.