use @define(LAYOUT,{'table','list','deflist'}) to choose between table, ul, ol ('list' and ABBRV_TYPE='index') and definition lists for displaying bibtex entries.
$bib->index is now displayed as a number, not a number in brackets, for compatibility with list values. however this is invisible to the user because the brackets are added in getAbbrv().
bib2html now includes the echoing of links.
