manual: Fix up invalid header and standards syntax.
This commit handles exceptional cases of invalid syntax for the
@standards conversion script.
* manual/crypt.texi: Move a comment out of an @*x list.
* manual/filesys.texi: Refactor some comments, one of which
looks like a standard. Fix incorrectly separated standards.
* manual/locale.texi: Invert an annotation.
* manual/resource.texi: Fix incorrectly separated standards.
* manual/time.texi: Refactor a @vtable that obscures an
annotation.
* manual/users.texi: Refactor multiple headers to occupy a
single @comment.