Custom memory handler fixes

- Make all custom memory handler be defined through a single
  preprocessor symbol to prevent incorrect mismatches.

- Reintroduce BOOST_SIMD_MEMORY_NO_BUILTINS to deactivate
  buitl-in aligned memory handlers without requiring custom
  handlers. This was erroneously removed in a previous commit.

- Amend doc to reflect new state of things.
Fix topology use of < in template context
Fix warning in shuffle test on MSVC
Merge pull request #679 from MetaScale/issue_675-msvc10_shuffle_fix

Fix for #675
Merge pull request #678 from MetaScale/fix_builtin_memory

Custom memory handler fixes
boost.simd: force_inline some functions for msvc2012
fuse aligned_malloc_override and aligned_realloc_override tests
Merge pull request #676 from timblechmann/topic/force_inlines

boost.simd: force_inline some functions for msvc2012
Split Black & Scholes demo

The old benchmark is now called nt2_merged as it works with
a fused operation setup. The realistic, multi-statement
demo is now in nt2 and use temporary tables etc...
Fix custom memory handlers test
erfc is speeded for float scalar and simd horner is used
and in horner a macro NT2_HORNER_RAT is added to ease the computation of rationnal fractions P/Q
changing benches ranges for erfc
add variant of shuffle-type functions for logical
changing ulps in complex sech for windows
fix #680, use setzero for integers and AVX
Merge pull request #682 from jtlap/ulp_in_cplx_sech

changing ulps in complex sech for windows
suppressing NT2_RAT in favor of NT2_HORNER_RAT
and adding a guarded test for infinity which was missing in the float case
issue #677, directly fill the header struct inside memory instead of copying it
after Mathias advise replacing rational fractions in erfc by polynomials with no loss
add size argument to free that says how many bytes were allocated