(Info-find-file, Info-find-node-2): Add history and toc.

(Info-find-file, Info-find-node-2): Add history and toc.
(Info-find-node-2): Simplify error message.
(Info-insert-dir): Use Info-following-node-name.
(Info-goto-node): Remove *info-history* and *info-toc*.
(Info-history): Create a node of the virtual history file.
(Info-toc): Create a node of the virtual toc file.
(Info-insert-toc): New arg `curr-file' for reference file names.
(info-apropos): Remove redundant var binding for temp-file.
(Info-index, Info-index-next, Info-mode): Doc fix.
(Info-goto-emacs-command-node): Don't jump to *info* from
non-*info* Info buffers.
(Info-fontify-node): Don't show the file name of external
references if `Info-hide-note-references' is `hide'.  Don't hide
newlines at the end of paragraphs.