(WIP) Joining linear mixed cluster and sharing latest model data.

Now the distributed machine learning is unstable.

Iterative Parameter Mixture(IPM) is not good for distributed computing.
Because it ignore cases like leaving & join cluster.

In this work, we implement **distributed computing proof IPM**.
It should,
- Be aware outdated model data, it should be update.
- Newbie process should get model from other cluster machines.
- if the latest machine crushes, left server should go with as late as possible data.

Simultaneously, in this pull-request, I'll prove issues #496 #478 #470 #485 #479 #227 (*oh! it's old*) too.