Replacing annotation classes by there fully qualified name 

The aim is to allow checking for annotations not available when packaging AA or even when compiling a project that uses AA

@mathieuboniface & @DayS please look at this: it changes the way we register new annotations. 

You may feel it's not "clean", since using class FQN as Strings is way more error prone then directly using classes. That's true. However, this was needed to handle Otto annotations without adding them to the classpath.