doc: mention more functions added in cygwin 1.7.0

doc: mention more functions added in cygwin 1.7.0

* doc/posix-functions/fwprintf.texi: Mention recent cygwin 1.7.0
addition.
* doc/posix-functions/fwscanf.texi: Likewise.
* doc/posix-functions/swprintf.texi: Likewise.
* doc/posix-functions/swscanf.texi: Likewise.
* doc/posix-functions/vfwprintf.texi: Likewise.
* doc/posix-functions/vfwscanf.texi: Likewise.
* doc/posix-functions/vswprintf.texi: Likewise.
* doc/posix-functions/vswscanf.texi: Likewise.
* doc/posix-functions/vwprintf.texi: Likewise.
* doc/posix-functions/vwscanf.texi: Likewise.
* doc/posix-functions/wcscasecmp.texi: Likewise.
* doc/posix-functions/wcsdup.texi: Likewise.
* doc/posix-functions/wcsftime.texi: Likewise.
* doc/posix-functions/wcsncasecmp.texi: Likewise.
* doc/posix-functions/wprintf.texi: Likewise.
* doc/posix-functions/wscanf.texi: Likewise.
* doc/glibc-functions/gethostbyname2.texi: Likewise.

Signed-off-by: Eric Blake <ebb9@byu.net>