Fixed hashmap issues in AdminClient raised during code review. Added '--parse-only' option to ConsistencyFix.

src/java/voldemort/client/protocol/admin/AdminClient.java
- Added hashCode & equals methods to AdminClient.Nodestore
- cleaned up getSocketStore to not leak concurrently created socket stores.

src/java/voldemort/utils/ConsistencyFix(CLI).java
- added parse only flag which limits that actions of the fixer to bootstrapping and parsing the input file.