MFC r256646, r256767, r257038:
  When installing updates, install new directories first and remove old
  directories last.

  Allow ~ in file names so libtool droppings in contrib don't break updates.
  It has happened twice now, and is likely to happen again.

  Be more selective when filtering for lib*.so.N files.  These are deleted
  at the end of the upgrade process, after warning users to upgrade any
  3rd party software (e.g., from the ports tree) which might link to the
  libraries being removed.

Errata Notice:  FreeBSD-EN-13:04.freebsd-update
Approved by:	so
MFC r257879:

Fix typo in r256646: We want to generate lists of directories in
INDEX-OLD and INDEX-NEW and compare them, not generate the same
list of directories from INDEX-OLD twice...

Pointy hats to: cperciva & everybody who didn't proofread
		EN-13:04 enough
Errata Notice:	FreeBSD-EN-13:05.freebsd-update
Approved by:	so
Fix bsnmpd remote denial of service vulnerability. [SA-14:01]

Fix ntpd distributed reflection Denial of Service vulnerability.
[SA-14:02]

Fix BIND remote denial of service vulnerability. [SA-14:04]

Disable hardware RNGs by default. [EN-14:01]

Fix incorrect coalescing of stack entry with mmap. [EN-14:02]

Approved by:	so
Apply FreeBSD releng/9.2 fixes into feature/unified_freebsd