Added support for non-lazy classes and categories

Added class and category duplicate prevention.
Added scanning the (__DATA, __objc_nlclslist) and (__DATA, __objc_nlcatlist)

This refers to issue 44: non-lazy classes/categories can appear solely in __objc_nlclslist/__objc_nlcatlist. If so, class-dump will not dump them.

HTH.
Regards.