NBBC 2.0

This version breaks backwards-compatibility with the 1.x version of NBBC which is why it has been given a major version number update even though no significant functionality has been added. Here are a summary of changes.

• All core classes have been moved into the Nbbc namespace to support PSR-4 autoloading and become a full composer library.
• PHP 4 is no longer supported. The minimum version of PHP required is now PHP 5.4.
• All properties on the BBCode class have been protected and must now be accessed with getters/setters.
• The URL auto-detection has been rewritten. It supports more general cases, but has removed support for some edge cases such as email addresses with an IP address domain.
• Images and smileys no longer check to see if files exist locally. This removes auto-generated image sizes too.

In addition to backwards-compatibility breaking changes there have been a few other changes that should not break backwards compatibility.

• Tests have been moved into a PHPUnit test suite.
• Calls to the EmailAddressValidator have been replaced with PHP's filter_var() function.
• Calls to the Profiler have been removed from the BBCode class. There are plenty of profiling tools out there now that don't bloat the code.
• The "@" error silencing operator has been removed wherever possible.