(Info-extract-menu-node-name): When looking for end of

(Info-extract-menu-node-name): When looking for end of
menu item, don't stop at first ":"; instead, continue
until trailing context is either a space or newline.
(Info-complete-menu-item): Change var `pattern' to allow ":" in menu item.
(Info-menu): Likewise, for regexp used in backwards search.
(Info-try-follow-nearest-node): Remove case added in previous edit.
Instead, change the regexp in the following case to allow ":" in menu item.
(Info-fontify-node): Fix bug: Handle `next-property-change' returning
point-max as "hasn't already been done".