Threads refactoring

Threaded architecture refactored.

3 specialized threads and others used in a thread pool way.

The "thread pool" is still not entirely tested and effective.

Basic usage should be simplified as before :pray: 

Please @BoucherAnthony try i on your thread machine. Verify that it create you just 1 taskthread, and not 5 for 8 thread cores.

I encourage you to merge as fast as possible because a __lots__ of file have been modified / deleted :baby_chick: 

It still need a lot of work, particulary on the task scheduler, I'll work on that soon, but I prefere to do a first PR with that.

Merry christmas :santa: 

![image](https://cloud.githubusercontent.com/assets/1561121/5519965/2707ea88-893a-11e4-8031-4e35b0dfa5ca.png)