CMS Diagnostics - Add unit threshold time millisec configuration

In CMS Diagnostics [1], I guess we can add @unitThresholdMillisec (long) for unit threshold.
So, when the property is set to a non-negative value (>=0), it should not print out any HDC task taken less than the threshold value.

[1] http://www.onehippo.org/library/concepts/request-handling/cms-diagnostics.html