OPENDJ-1023 OPENDJ-1024 (CR-4092) Provide duration and warm-up parameters to the xxxrate tools
Adding two new parameters to the xxxrate tools, maximum duration time and warm-up duration time.

** PerformanceRunner.java
* Adding a timer thread for the max duration feature and add warm-up implementation.
** AddRate.java SearchRate.java
* Adding resetStats method to reset local statistics (i.e extra columns)
** tools.properties
* Adding warm-up message
** AuthRateITCase.java
** Adding a test with warm-up phase