Merge branch 'mdw/cpu-dispatch'

* mdw/cpu-dispatch:
  Add support machinery for ARM hosts.
  base/dispatch.c: Add (unused) machinery for probing ELF auxilary vector.
  Add support for AMD64 processors and Microsoft Windows.
  symm/rijndael-x86-aseni.S: Unify encryption and decryption with a macro.
  symm/rijndael-x86-aesni.S: Use xmm5 instead of xmm7.
  symm/*.S: Symbolic names for shuffles.
  symm/chacha-x86-sse2.S: Fix the register allocation comment.
  Preprocess the assembler files.
  configure.ac: Improve the host CPU family detection.
  base/dispatch.c: Indent some preprocessor definitions properly.
  Add a pile of debug output around the CPU dispatching machinery.
  base/dispatch.c: Add documentation for some internal functions.
  base/dispatch.c: Add in more useful section markers.
  Support Intel's AES Native Instructions where available on x86 hardware.
  symm/: New SSE2 implementations of Salsa20 and ChaCha.
  symm/salsa20.c, symm/salsa20-core.h: Permute input matrix for SIMD.
  debian/rules: Run tests twice, once without any detected CPU features.
  base/dispatch.c: Check operating system support for XMM registers.
  configure.ac, base/dispatch.[ch]: CPU-specific implementations.
  configure.ac: Arrange to have an assembler available.

Conflicts:
	configure.ac
	symm/Makefile.am