Change makefiles so that html files are automatically installed and

Change makefiles so that html files are automatically installed and
part of dist. No more maintenance of HTMLFILES ...
Section about fields and character maps moved to separate chapter
because it relates to all record types (not only grs).
Added lots of id attributes to sections to get rid of docbook xsl
warnings and to ensure proper HTML file name.
Added Olegs paper on MARC indexing to grs chapter.