CL33619: Contributor's Guide - Detailed logic of choosing the best brick

[tatsuya6502]

Add some detailed descriptions of how the best brick is chosen in a chain.

[tatsuya6502]

Now I think Chapter 9. Dynamic Cluster Reconfiguration of Hibari System Administrator’s Guide will be more appropriate place for this topic than Hibari Contributor's Guide. Some code samples will go under 14.3. Change a Chain: Add or Remove Bricks

Also I feel bit strange to have table related operations in chapter 9. I would create another chapter Working with Tables and move first two sections ( Adding a Table and Removing a Table ) there.