Added consistency check tool. Support single partition only
Updated ConsistencyCheck.java for new feature
First step towards a consistency fixer tool.

src/java/voldemort/utils/ConsistencyFix.java
- CLI and initial implementation of fixer
- each invocation fixes one key for one store on one cluster

src/java/voldemort/client/protocol/admin/AdminClient.java
- added repairEntry method. Very much a work-in-progress.

src/java/voldemort/utils/ByteUtils.java
- added fromHexString helper function. (Sister function of toHexString)

test/unit/voldemort/utils/ByteUtilsTest.java
- improved tests for to/from HexString
wrap up the consistency tool
fixed a bug where the program does not sweep latest-version-consistent keys correctly
Added multiple-key options to ConsistencyFix tool.

src/java/voldemort/utils/ConsistencyFix.java
- Options for keys:
  --key : single key
  --keys : list of keys on command line
  --key-file : file of keys, one per line.
  keys are in hexadecimal.
- A bunch of TODOs for next step code cleanup, hardening, improving.
Cleaned up initial implementation of ConsistencyFix for preliminary code review.

src/java/voldemort/client/protocol/admin/AdminClient.java
- annotated repairEntry method with TODO items to get review feedback on
- Created new type QueryKeyResult to get rid of a struct of type  Pair<ByteArray, Pair<List<Versioned<byte[]>>, Exception>>

src/java/voldemort/utils/ConsistencyFix.java
- added output file to list non-fixed keys in
- modulate output based on verbose flag
- refactored giant method(s) into smaller methods
- cleaned up TODO comments for review feedback

test/unit/voldemort/client/AdminServiceBasicTest.java
- uses QueryKeyResult type

src/java/voldemort/VoldemortAdminTool.java
- uses QueryKeyResult type
Added non-zoned cluster(multiple bootstrap url) support for consistency check; This uses value hash for comparing values instead of version object