This commit introduces HotSpot JVM monitoring through the low-level
"jvmstat" interfaces, which are exposed through the MMAPed "HSPerfData"
file.  jvmstat offers much more detailed analysis of the internals of
VM health than MX management beans or even JMX ever could.

= Milestone for Next Iterations (Need to start code review now.)
- Full documentation of the metrics and what they mean with backtracked
  links into HotSpot source code.  I have most of this information in
  the form of raw notes, so annotation shouldn't take too long.