Existence of finalizer causes experiment to fail (@ instrument=micro)

```
During prototyping of an object pool [1], I added a finalizer on the handle to
detect resource leaks (e.g. due to race conditions). When running a simple
benchmark with Caliper 1.0b1 it consistently failed by exceeding the trial
period. I temporarily reverted 0.5rc1 whose behavior differs enough that my
benchmark worked.

Later when actually performance tuning and my tests were robust, I removed the
finalizer. This improved performance as expected, as well as let 1.0b1 succeed.

[1] https://github.com/ben-manes/multiway-pool
```

Original issue reported on code.google.com by `Ben.Manes@gmail.com` on 14 Jul 2013 at 10:38