Nist test failed on my new i7. New parameters work.
CMakeLists: -fpic and variadic max

-fpic instead of -fPIC removes a warning in gcc 4.8
variadic max enables programs with higher settings than default to
link with spii.
Travis: Output test result on failure. [ci skip]
Handle random number generation better.
Do not use const& to std::string.
Get rid of some unsigned/signed warnings.