Wherever we use k5alloc with a multiplication in the size parameter,,
use the new k5calloc helper function instead.

Commit 4b0985f8573840838bcfa8ec1df3dcd39a3dbf15 went a bit too far in
pruning the placeholder makefiles for the openssl and nss crypto
modules.  We need enough boilerplate to create OBJS.SH in each
directory.

If yasm and cpuid.h are present on a Linux i686 or x64 system, compile
the modified Intel AES-NI assembly sources.  In the builtin AES enc
provider, check at runtime whether the CPU supports AES-NI
instructions and use the assembly functions if so.

Remove functions we don't need.  Add macros to redefine functions with
an appropriate namespace prefix.

Add assembly files from the Intel AESNI Sample Library, version 1.2,
which implement AES encryption using AES-NI instructions.  Trailing
whitespace was removed.

In preparation for AES-NI support, adjust the block encryption helpers
in the AES enc provider so that the cache is only touched by helpers,
and reframe the CTS operations in terms of CBC operations.  Change the
Camellia enc provider as well for consistency.

Expand the concept of an IOV block state into a cursor which remembers
the IOV set being iterated over, the block size, and both input and
output positions.  Eliminate the no-copy inline block getter for now,
but provide helpers to grab contiguous chains of blocks from a cursor.
Also provide an inline helper to sum the total length of an iov chain.

Provide default values in pre.in for PROG_LIBPATH, PROG_RPATH,
SHLIB_DIRS, SHLIB_RDIRS, and STOBJLISTS so that they don't have to be
specified in the common case.  Rename KRB5_RUN_ENV and KRB5_RUN_VARS
to RUN_SETUP (already the most commonly used name) and RUN_VARS.  Make
sure to use DEFINES for local defines (not DEFS).  Remove some other
unnecessary makefile content.