[core] Fixing squid:S1319 -  Declarations should use Java collection interfaces such as "List" rather than specific implementation classes such as "LinkedList".
(manolama - updated bindings added since the PR)

Signed-off-by: Chris Larsen <clarsen@yahoo-inc.com>

[core dynamodb googledatastore infinispan] Fixing pmd:UnnecessaryConstructor - Unnecessary constructor, squid:EmptyStatementUsageCheck - Empty statements should be removed

[cassandra cassandra2 dynamodb hbase098 hbase10 jdbc s3] Fixing squid:S1481 - Unused local variables should be removed

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.

Replaces numeric status codes with a canonical set of Status objects,
each with a short name and description.
Bindings with more specific errors (e.g., timeouts) return additional
statuses.

This changes the default output from messages like:

   [UPDATE], Return=0, 511

To:

   [UPDATE], Return=OK, 511

I have fixed a bug in insert() and delete() methods.There are also
some cosmetic changes to readme and properties files.