include <sys/endian.h> for both the non-tools build,
and the tools build on a host where the file exists.

Fixes a build problem on FreeBSD, reported by Herbert J. Skuhra, where
tools/compat's configure detected that be32dec() and friends were
available in the host's <sys/endian.h>, so tools/compat did not provide
its own versions.
Call prop_dictionary_get_uint32 with uint32_t
Imported and adapted from FreeBSD svn r272166 and r272207; this fixes
false positives for products of primes larger than 2^16. For example,
before this commit:

  $ /usr/games/primes 4295360521 4295360522
  4295360521
but
  $ /usr/games/factor 4295360521
  4295360521: 65539 65539

or
  $ /usr/games/primes 3825123056546413049 3825123056546413050
  3825123056546413049
yet
  $ /usr/games/factor 3825123056546413049
  3825123056546413049: 165479 23115459100831

or
  $ /usr/games/primes 18446744073709551577
  18446744073709551577
although
  $ /usr/games/factor 18446744073709551577
  18446744073709551577: 139646831 132095686967

Incidentally, the above examples show the smallest and largest cases that
were erroneously stated as prime in the range 2^32 .. 3825123056546413049
.. 2^64; the primes(6) program now stops at 3825123056546413050 as
primality tests on larger integers would be by brute force factorization.

In addition, special to the NetBSD version:
. for -d option, skip first difference when start is >65537 as it is incorrect
. corrected usage to mention both the existing -d as well as the new -h option

For original FreeBSD commit message by Colin Percival, see:
http://svnweb.freebsd.org/base?view=revision&revision=272166
debug ld_sdmmc with LD_SDMMC_DEBUG instead of SDMMC_DEBUG
dm_target_t reference count is modified with atomic_{inc,dec}_32 so should
be uint_32_t not int
Use devmajor_t not int
Work around pedantic compiler
Use uint32_t for blocksize as per other uses and to fix warnings