Improvement/3.x/partitioncleanup

Some cleanup in the PartitionView

- removed unused code
- simplified code
- removed unwanted dependencies to PartitionImpl

This is needed for performance improvements because the PartitionImpl can now be tuned a lot easier since it has become a implementation detail.

[edit]
According to my latest measurements, I'm spending up to 33% of the time reading out the replica id's. I know how to improve it, but I need to have this cleanup in place to do it nicely.

![screenshot - 12302013 - 08 41 03 am](https://f.cloud.github.com/assets/105243/1821066/6cd0979e-711d-11e3-846b-2114478b705a.png)