Parameterized

[ikoryakovskiy]

I personally loved the library, but having parameterized callback was a useful option that was missing. Therefore, I added this functionality. With this functionality it is possible to call same callback function by different threads, and implement different functionality depending on the parameter. I did not modify documentation because I though it is better if you take a look at the code yourself. Let me know that do you think.

[CAHEK7]

Could you check #7 and #27.