add warning exception for large powerpc vectors
adding pi^2/6 constant needed by spence
improving and correcting spence
adding exhaustive tests in euler for spence (also erf and erfc)
Adapt beta cover ULP in SIMD
Merge pull request #703 from jtlap/euler_spence

Euler spence
fix #704: add fast_iround2even on scalar single-precision for SSE
erf and erfc are co-improved and a join details kernel file is added
Merge pull request #705 from jtlap/improve_erf

erf and erfc are co-improved and a join details kernel file is added
suppressing the unused param which is useless
Merge pull request #706 from jtlap/unused_param_in_erf_kernels

suppressing the unused param which is useless
increasing ulp threshold to 6 in normcdf unit test
use 'ex' variable instead of recomputing 'exp(-xx)'
fix includes and indenting in erf
clean up includes in expni
try to make sense ouf of erf/erfc inbtrue tests
fix bad nbtrue usage in gamma/fast_gamma
support more operators in fixinclist. '&', '<' and '>' currently disabled due to confusion with references and templates