cbrt only needs fast_frexp
Missing log constants
Fix NO_NAN include handling in scalar sign
guarding denormal tests and adding some to fr/ldexp unit tests
headers fixed in ieee.functions/simd/common
fixed warning in scalar signnz.hpp
fixing includes in frexp, ldexp, fast_frexp and fast_ldexp
fix typo in fast_ldexp + remove unused typedef
Merge pull request #641 from jtlap/cbrt_only_need_fast_frexp

cbrt only needs fast_frexp
Merge pull request #645 from jtlap/ldfrxp_tests

guarding denormal tests and adding some to fr/ldexp unit tests
Merge pull request #642 from jtlap/log_doesnt_always_need_abs

 abs is needed in log only if denormals are enabled
Merge branch 'master' into simplifying_mantissa

Conflicts:
	modules/boost/simd/base/include/boost/simd/ieee/functions/simd/common/mantissa.hpp