Autodetect numer of cpu's

[jonschipp]

Need a portable way to detect number of cpu's to automatically configure cpu-set.
Tested getconf _NPROCESSORS_CONF on Linux and OSX. Without the underscore getconf NPROCESSORS_CONF returns number of processors on IllumnOS

[jonschipp]

The only use case I can think of right now is to allocate all cores for containers except 0.. automatically on multicore systems to prevent the system from becoming fully unresponsive should an issue arise