Adding debug log messages for CoordinatorService
Adding debug log messages for CoordinatorService - adding review comments
fix problems in admin tool

1. fix bug in validating store names on nodes
2. rename some functions
3. use node id rather than node object in admin command functions
Releasing Voldemort 1.8.3
Added the ability to query a single store using AdminClient / admin tool
Addressing review comments for fetch_single_store