eliminate rare chance of race condition

One could loose the response of the spawned process due to too quick
response message. So add lintener first, then call parallel process.
making jshint happy. Do not redefine a variable.
fixing variable overwriting in test (thanks JsHint!)
fixing performance test for dual core machine
remove unused variables, more precise checks (JsHint)
start the parallel process after you assigned the listener.
Merge pull request #3 from kurellajunior/master

Minor changes and enhancements