add benchmarklog that logs the benchmark output to a file similar to querylog
remove unitTest cookie check, this is not required as unittests have their own config where benchmark is disabled
rename benchmarkLog to benchmarkCounter

- makes more clear what this setting actually does
- we can use benchmarklog for the log file
rename benchmarklogfile to benchmarklog, similar to querylog and eventlog
Merge pull request #53 from nsams/benchmarklog

add benchmark log similar to querylog