(CFACT-70) maintenance - refactor usage of kstat to a wrapper

kstat APIs are used by solaris and other systems like free bsd to fetch kernel statistics. This patch refactors the kstat invocations into a simpler wrapper that handles both errors and data retrieval.
explicit template specializations should be declared immediately following the template.  They can be defined here, but  definitely need to be visible before anyone instantiates the template.