Create php-login.php

Add a common file to check PHP prerequisites, load common variables, libraries, classes and functions necessary for php-login script to work properly.
Update edit.php - To include php-login.php
Update index.php - To include php-login.php
Update password_reset.php - To include php-login.php
Update register.php - To include php-login.php
Merge pull request #1 from devplanete/patch-1

php-login-advanced: Add a common include file