Manual restructure and license change

A few weeks ago the manual was restructured to improve navigation and make room for per-extension chapters and usage examples along with improved documentation for object oriented extensions. The most noticable changes are the function reference, predefined variables, context options and parameters and predefined exceptions manual pages, for which we would really appreciate feedback on. The upcomming PHP5.3 release introduces several major features such as namespaces, closures, late static bindings, internationalization functions, INI sections, and Phar among others. We would really appreciate any and all help we can get improving the documentation. In related news, the manual was relicensed recently and is now covered by the CreativeCommons Attribution license.