Adds new multi-fetch functionality

The Bucket interface and DomainBucket are now capable of
returning / using a new MultiFetchObject that will parallelize
a set of fetch operations using a threadpool and return a
list of futures.
Fixed getMaximumPoolSize() removed ifModified()

getMaximumPoolSize was erroniously returning the corePoolSize and
ifModified(VClock vclock) is not applicable to a multi-fetch.
Registering Joda time support with JSONConvertertor's object mapper, as it was removed earlier
Fixed typos, copyright, added usage example

Also removed get/set MaximumPoolSize as it has no effect with
an unbounded work queue - only corePoolSize is considered.
Merge pull request #225 from basho/add_multi_get

Adds new multi-fetch functionality
Merge pull request #229 from sargun/master

Joda Time
bumped jackson-datatype-joda to v2.1.2
Allows withoutFetch() in DomainBucket

This is a simple change allowing a boolean to be set when
constructing a DomainBucket that is then used to call
withoutFetch() on the underlying StoreObject

Addresses #232
Merge pull request #234 from basho/gh233-add-without-fetch-to-domainbucket

Allows withoutFetch() in DomainBucket