Choose between queries per minute and queries per second (or updates per minute/second)

[GoogleCodeExporter]

On this version, the user can only specify the number of queries (or updates) 
per minute. This is good for cases when the queries expected are not too hi, 
but its a problem when queries expected are many (500 qps is translated to 
30,000 qpm). User should be able to specify the number of queries and the unit 
of time (second or minute).

Original issue reported on code.google.com by [email protected] on 24 Sep 2010 at 2:01