Drop bunch of macro definitions needlessly duplicated with rpm
    
    Specifically, the following are gone from here now: %_prefix,
    %_sysconfdir, %_infodir, %_mandir, %_defaultdocdir, %_configure,
    %makeinstall, %debug_package, %_use_internal_dependency_generator,
    %_missing_doc_files_terminate_build, %_unpackaged_files_terminate_build