Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Split tolower/toupper code from usual xlat16 kiconv table, and make it
possible to do tolower/toupper independently without code conversion.

Submitted by: imura (but bugs are mine)
Obtained from: http://people.freebsd.org/~imura/kiconv/
(1_kiconv_wctype_kern.diff, 1_kiconv_wctype_user.diff)

Fix kiconv on the 64bit plathomes.

- Correct idxp pointer to point the properly address of the
each array of the kiconv character conversion tables,
so that character conversion work properly when file
systems are mounted with kiconv options.

- The definition of ICONV_CSMAXDATALEN was also bogus
because it was defined as if all machines were 32bit
computers.

Tested on: amd64
MFC after: 1 month

Make msdosfs long filenames matching case insensitive again.

PR: 59765
Submitted by: Ryuichiro Imura <imura@ryu16.org>

- Support for multibyte charsets in LIBICONV.
- CD9660_ICONV, NTFS_ICONV and MSDOSFS_ICONV kernel options
(with corresponding modules).
- kiconv(3) for loadable charset conversion tables support.

Submitted by: Ryuichiro Imura <imura@ryu16.org>