NOTES.UNIX: add additional note about --enable-new-dtags

    $ ./config --prefix=/usr/local/ssl --openssldir=/usr/local/ssl \

        -Wl,-rpath,'$(LIBRPATH)'

 On modern systems using GNU ld.so, a better choice may be to use the

 new dtags, like this:

    $ ./config --prefix=/usr/local/ssl --openssldir=/usr/local/ssl \

        -Wl,--enable-new-dtags,-rpath,'$(LIBRPATH)'

 This sets DT_RUNPATH instead of DT_RPATH.  DT_RUNPATH is considered after

 the environment variable LD_LIBRARY_PATH, while DT_RPATH is considered

 before that environment variable (which means that the values in that

 environment variable won't matter if the library is found in the

 paths given by DT_RPATH).