For the XML output's terminal element, rename @number to @token-number,

and add @symbol-number.  In the nonterminal element, rename @number to
@symbol-number.  Discussed starting at
<http://lists.gnu.org/archive/html/bison-patches/2007-10/msg00040.html>.
* data/xslt/xml2text.xsl (xsl:template match="terminal"): Update for
renames.
(xsl:template match="nonterminal"): Likewise.
* data/xslt/xml2xhtml.xsl (xsl:template match="terminal"): Likewise.
(xsl:template match="nonterminal"): Likewise.
* src/print-xml.c (print_grammar): Implement.