Introduce support for @QueryHandler, @QueryDispatcher and @Query

[zambrovski]

There are query handlers (methods) residing inside of a projection (aka Query model). If those could be annotated with @QueryHandler and their parameters with @Query then the CQRS API would be completed with @QueryDispatcher, having both the command and the query side kind of symmetric.

 @interface QueryHandler {
   String name() default "";
   String namespace() default "";
 }

 @interface Query {
   String name() default "";
   String namespace() default "";
 }

 @interface QueryDispatcher {
   String dispatches() default "";
 }

What do you think?