Add *info*<[0-9]+> to same-window-regexps instead of

Add *info*<[0-9]+> to same-window-regexps instead of
same-window-buffer-names.
(info): New arg `buffer'.  Use it.  Doc fix.  Read file name for
non-numeric prefix argument, append the number to the buffer name
for numeric prefix argument.
(info-other-window): Bind same-window-regexps to nil.
(Info-reference-name): Rename to Info-point-loc.
(Info-find-node-2): Call forward-line for numeric Info-point-loc,
and Info-find-index-name for stringy Info-point-loc.
(Info-extract-menu-node-name): New arg `index-node'.  Use regexp
without middle `.', but with final `.' and optional line number
for it.  Set Info-point-loc for index nodes.
(Info-index): Remove middle `.' from index entry regexp.
Modify line number regexp.
(Info-index-next): Decrement line number.
(info-apropos): Remove middle `.' from index entry regexp.
Add optional line number regexp at the end.  Add matched value
for line number to the result list and insert it to the buffer.
(Info-fontify-node): Hide index line numbers.
(Info-goto-node): Replace "\\s *\\'" by "\\s +\\'" to not trim
empty matches.
(Info-follow-reference): Use `str' instead of
Info-following-node-name-re.
(Info-toc): Use full file names.  Set Info-current-node to "Top".
(Info-fontify-node): Compare file names without directory name.
(Info-try-follow-nearest-node): Don't set Info-reference-name.
Set second arg of Info-extract-menu-node-name for index nodes.
(info-xref-visited): Use magenta3 instead of magenta4.
(Info-mode): Add info-apropos to docstring.