Review Board 1.7.22

Consolidate membership management

Review Request #4729 - Created April 15, 2012 and updated

Alexander Shraer

Currently every server has a different configuration file. With this patch, we will have all cluster membership definitions in a single file, and every sever can have a copy of this file. 
Many tests were updated to work with the new configuration format. tests backward compatibility.
Review request changed
Updated (April 19, 2012, 4:01 p.m.)
updated patch following Flavio's comments