added SimpleDBI library, downloaded router.php and database.php, configured bootstrap.php, added board.sql, modified core.php
modified: app_exception, bootstrap, html_helper, default, .htaccess, SimpleDBI; added thread_controller, validation_helper, comment, thread
added Registration with validation and Login(no session)
added pagination helper (incomplete)
fixed comments bug
fixed pagination library
added pagination on comments
added 404 page, modified usersignup and pagination
Followed coding standards version 1
pair code review v1.0
pair code review v1.1
added phpdocs to all functions
Followed coding standards version 1.1
Revised code as per code review v1.0
Revised code as per code review v1.1
finalized code review
Merge pull request #1 from gromualdo/dev_1.0

Board Exercise (Login, Registration, Pagination)