Several improvements for PHP-Autoload-Manager

The improvements include:

* autoloadManager::generate() now returns a boolean value - TRUE if no errors occurred, FALSE otherwise.
You can get a list of errors using autoloadManager::getErrors() and check for errors using autoloadManager::hasErrors()

* When regenerating autoload file on class load - throws an exception if a class with the same name is specified in two or more files

* When saving autoload file - creates directories along the way, if they are not yet created

* If a class file has been moved or renamed - rebuild autoload file