Organize hashing in libc.

Remove workaround for ancient HTML generation code.

\\ -> \e

u_intN_t -> uintN_t

Add man-pages forgotten in previous commit.

this moved to common/lib/libc/hash

change #include <sys/endian.h> => #include <machine/endian.h> so that
it's (more) consistent in the tree; this, along with changing tools/compat's
autoconf detection from AC_CHECK_FUNCS to AC_CHECK_DECLS makes the vast
majority of htobe16 and friends' redefinition errors bite the dust.
Tested with -current and FreeBSD.

Fix weak aliasing after recent changes.

Inspired by comments from christos@, xtraeme@, mlelstv@, mhitch@, mrg@,
and uwe@; all the bugs are mine.

Need namespace.h here too.

Organize hashing in libc.

branches: 1.6.10;
Fix replicated typo

More cleanup after sha2.h and rmd160.h moved house

Rename "hash.c" to "hashhl.c" since this is included from *hl.c files.
The name "hash.c" is already used in db/hash/hash.c, and having duplicated
names, aside from it being bad style, breaks the tools/nbcompat build
because it picks the wrong hash.c file. Thanks to greg for helping debug
this.

The weak alias macros can only work before namespace.h gets included because
when the strings get expanded we gain an _ from namespace.h. So define a
macro to point to the appropriate include file for the hash function, and
include the hash function later, from the .c file we always include. This
allows us to eliminate the hack of including namespace.h twice as well as
nbtool_config.h.

Use crypto/rmd160.h.

Organize hashing in libc.