phm Instant Messenger Core: Manage users and friends that exchange messages

This class can be used to manage users and friends that exchange messages.

It can create and retrieve records in MySQL database tables that contain information of users, friends and messages that they may exchange.

Currently the class implements several operations like authenticating users, change user passwords, retrieve account password reminder question and answer, create user accounts, add friends, search for friends, retrieve user nick names, messages sent from one user to a friend,retrieve messages received by an user, accept friend request, give list of friends, show friends awaiting accept, and allow bbcode for use in web browsers.