MFC of 276737, 322200, 322201, 322271, and 322297

276737: Remove old ioctl use and support
322200: Remove (broken) search for alternate superblocks
322201: Show differences when alternate superblock fails to match
322271: Cleanup for 322200.
322297: Restore fsck_ffs ability to find alternate superblocks

Discussed with: kib, imp
Differential Revision: https://reviews.freebsd.org/D11589
Approved by: re (kib)

MFC r265164: Small cleanup: mostly whitespace vs. tabs.

MFC r264889: newfs_msdos: Correct min/max cluster counts for FAT12/16/32

FAT12 1..4084
FAT16 4085..65524
FAT32 65525..

This is required for interoperability with other FAT implementations,
and in particular UEFI.

Obtained from: NetBSD
Sponsored by: The FreeBSD Foundation

MFC r269953:
Use "NO NAME" as the default unnamed label.

Microsoft recommends avoiding the use of spaces in the
string structures for FAT. Unfortunately they do just
that by default in the case of unlabeled filesystems.

Follow the default MS behavior to avoid confusion in
common tools like file(1). This was actually the
default behavior before r203868.

Obtained from: NetBSD (CVS rev. 1.39)

MFC r269953:
Use "NO NAME" as the default unnamed label.

Microsoft recommends avoiding the use of spaces in the
string structures for FAT. Unfortunately they do just
that by default in the case of unlabeled filesystems.

Follow the default MS behavior to avoid confusion in
common tools like file(1). This was actually the
default behavior before r203868.

Obtained from: NetBSD (CVS rev. 1.39)