doc: use dot/'•' rather than point/'.'

AFAICT, "dotted rule" is a more frequent synonym of "item" than
"pointed rule".  So let's migrate to using "dot" only.

* doc/bison.texi: Use dot/'•' rather than point/'.'.

* src/print-xml.c (print_core): Use dot rather than point.  This is
not backward compatible, but AFAICT, we don't have actual user of the
XML output (but ourselves).  So...
* data/xslt/xml2dot.xsl, data/xslt/xml2text.xsl,
* data/xslt/xml2xhtml.xsl, tests/report.at: ... adjust.

src/gram.h

@@ -229,7 +229,7 @@ print_dot_fallback (unsigned int code _GL_UNUSED,
 }
 
 /* Print "•", the symbol used to represent a point in an item (aka, a
-   pointed rule).  */
+   dotted rule).  */
 static inline void
 print_dot (FILE *out)
 {

src/print-xml.c

@@ -89,7 +89,7 @@ print_core (FILE *out, int level, state *s)
           if (reds->lookahead_tokens && red != -1)
             {
               xml_printf (out, level + 1,
-                          "<item rule-number=\"%d\" point=\"%d\">",
+                          "<item rule-number=\"%d\" dot=\"%d\">",
                           r->number, sp1 - sp);
               state_rule_lookahead_tokens_print_xml (s, r,
                                                      out, level + 2);
@@ -100,7 +100,7 @@ print_core (FILE *out, int level, state *s)
 
       if (!printed)
         xml_printf (out, level + 1,
-                    "<item rule-number=\"%d\" point=\"%d\"/>",
+                    "<item rule-number=\"%d\" dot=\"%d\"/>",
                     r->number,
                     sp1 - sp);
     }