make MySQLi class accept "host:port" notation just like MySQL class
Add MySQLi example
Remove useless file
Misc improvements

- Remove SQLite mentions in inline comments
- Fix PDO for SQLite example
- Show PDO for MySQL example
- Fix sysdate() function for MySQL
Merge pull request #32 from ozh/ozh_ports

Accept "host:port" notation for MySQLi
Merge pull request #33 from ozh/pdo_doc

Misc PDO improvements