Final commit for frames/no-frames versions.

Final commit for frames/no-frames versions.

1) You can now compile (and install!) the two versions together
   typing make FRAMES=x" twice.
2) The default index.html is a patched copy of html_yes_frames/index.html
   when FRAMES=yes and is not there when FRAMES=no. [I don't know what
   to put there in this case! ;-(]

The only variable that must be set in the Makefile is the destination
directory.

Question: what should we do now? Keep only one of the two versions?
Keep both of them and add a first page in which the user can choose
the version he prefers? Put a link from one version to the other
and keep one as the default?