Specialized PHP exceptions using SPL Exceptions.
See http://php.net/spl.exceptions.php
Added the new exception types to the PHPDoc.

  - Specialized Exceptions in @throws
  - Multiple @throws for multiple throw
PSR-0 compliance

  - Renamed class
  - Renamed file as well
PSR-1 compliance

Removed ?> tag
PSR-2 compliance

  - Code style
Merge pull request #5 from izeau/psr-compliance

PSR compliance