Updates to specifying a cache class, added @Secure annotation.

Updated annot.cache to take an instance of any class implementing Doctrine\Common\Cache\Cache. Previously annot.cache accepted only a string which limited caching choices to existing Doctrine cache implementations that did not require any setup more complicated than an empty constructor. Now anything could be used as long as it implements the Cache interface. The string input still works as it always has, but is not recommended.

Added the @secure annotation. This provides the functionality included by the security trait.