Class#getDeclaredClasses(): exclude inner classes of inner classes

Inner classes can have inner classes, but getDeclaredClasses() is
supposed to list *only* the immediate inner classes.

Example: if class Reflection contains a class Hello that contains
a class World, Reflection.class.getDeclaredClasses() must not
include World in its result.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Implement Field#getGenericType()

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Merge pull request #112 from dscho/get-generic-type

Support Field#getGenericType()