Add Password authentication to Apache Server

This is to add password authentication to Apache web server. The password file used is the Linux password file. By doing this, apache authentication is linked to linux authentication.

Of course because web authentication password is passed in clear, SSL/HTTPS should be used if security is of any concern.

download and install the Mod_Auth_External module and the pwauth utility.

simply follow the instructions in INSTALL file.

One thing is to make sure the user id in pwauth config.h file is correct (corresponding to the "apache" user id).