This reverts commit 0e5866eb.

Restores #372

[googledatastore] Add a Google Datastore client

Revert "added S3 storage binding"

[S3] added S3 storage binding

Closes #413 

Addressing the last CR comment.

[googledatastore] Add cause to DBException

Copyright statement, better exception messages, etc.

1. Move documentation from the properties file to the README.md
2. Addressed a couple of comments in the code.
3. Added the checkstyle plugin and addressed all the violation (except
the TODO comment violation. I'd like to keep a TODO item in the code).

[googledatastore] Output debug logs in one line instead of multiple lines.

Will implement scan separately in the next pull request.

Add support to allow users to group entities in two different ways, and add documentations for the overall googledatastore.properties file.

Add a DB client for Google Cloud Datastore. This initial commit includes implementation of all CRUD operations (modulo scan), and integration into the rest of YCSB (pom.xml changes, etc)

Next few commits will include Scan/query support, single entity group support, and better documentation.

[elasticsearch] Checkstyle updates for Elasticsearch.

[redis] Checkstyle updates for the Redis binding.

[voldemort] Update binding to use the new Status class and also checkstyle updates.

[core] passing full fieldset for verification

When dataintegrity and readallfields are both true, pass the full field
set to db.read() so that the field values can be verified.

Fixes #496

[core] added return codes to VERIFY

[jdbc] removed semicolons from cached statements

Changed measurement latency to actual latency time of the verifyRow step
and now recording Status codes for verify operations.

Fixes #479

[kudu] Checkstyle updates for the Kudu binding.

[hbase10] Checkstyle updates for HBase 1.0 binding.

checkstyle updates.

Closes #477. This is #477 rebased against current master, with long
lines in commit messages wrapped.

Extend the dynamoDB client to support the HASH_AND_RANGE primary key
type. The default primary key type remains exactly the same as before:
HASH type. And the default behavior and processing logic also remains
exactly the same as before.

What's added is the support to benchmark a primary key type called
HASH_AND_RANGE which is one of two supported primary key types of
DynamoDB. Knowing the performance characteristics of the HASH_AND_RANGE
key is important for some users because that's the only practical way
for them to get strongly consistent query across multiple items.

See documentation in conf/dynamodb.properties for more details.

JDBC test cases

reverted a few things that were not necessary
* semicolon change - coming in another PR
* .gitignore change - no longer using derby

Code cleanup
* test scoped hsqldb
* removed derby artifacts and references
* setting driver class is not necessary
* cleaned up unused objects in delete
* now running cleanup on client
* removed old assert(true) stub

Had to fix the semicolon issue for Derby.
Ended up switching to HSQLDB becuase Derby does not support LIMIT.

Also fix a few README formatting issues.

        mvn org.apache.rat:apache-rat-plugin:0.11:check -D rat.numUnapprovedLicenses=5000

[core] Fix the build post the #461 merge.