Howto add a new library (in a new SUBDIR):

 - create new subdir and copy a recent Makefile into there              e.g. use ./REFENTRIES/Makefile
 - add a dependency vs 'links' or 'links_non_perl'                      in ../Makefile@ADD_links_non_perl

 - add it to the ARCHS_... definitions used for linking                 in ../Makefile@Individual_Programs_Section
   or
   add it to dependency list of TOOLS.dummy                             in ../Makefile@TOOLSLIBDEPENDS

   Please note: if the new library isn't added anywhere
        => it will not be build
        => unittests wont work

 - add all externally visible headers                                   in ../SOURCE_TOOLS/generate_all_links.sh@ALIVIEW

 - add a stub for (nonexisting) unit tests                              in ../Makefile@UNITS_WORKING
   or
   activate existing unit tests                                         in ../Makefile@UNITS_TESTED
   + create unittest-linkfile                                           e.g. use ./CB/needs_libs

 - call once:
   SOURCE_TOOLS/svn_apply_ignores.pl --apply

Important: Before committing the change, run a full rebuild!