adding maxflint as a helper to round
new round2even and associates
using if available C99 round and roundf
ceil and floor use round2even in common mode
combinatorial uses round2even
exponential uses round2even
trigo uses round2even
linalg uses round2even
round now is away from zero for half integers
idivide has round2even as supplementary choice
updating related CMakeLists.txt
bad include rdivide in lcm
include missing or wrong name (rdidide)
volatile is needed for scalar round2even
Merge branch 'round' of github.com:MetaScale/nt2 into round
missing include in negs
wrong type 'calar' in ellipke bench
merge master into round
rdivide was still included by divround.hpp
Merge branch 'round' of github.com:MetaScale/nt2 into round