Merge pull request #177 from YannRobert/IntroducingFindBugsMavenPluginOnTestsToo

Introducing find bugs maven plugin on tests too
just a refactoring : moved Attachment related stuffs to new class StdAttachmentCouchDbConnector. Existing methods now just delegates to it.
extended AttachmentCouchDbConnector in order to support Apache HttpEntity, providing a way for user applications to save an Object directly in a streamed way without relying on temporary ByteArrayOutputStream+ByteArrayInputStream, just by implementing an appropriate HttpEntity
avoid useless json-decoding and json-encoding of rawkeys, they can be kept as-is and passed to the query. This can be a big performance improvement in some cases.
using a ThreadLocal in order to maintain 1 instance of ObjectMapper per Thread, instead of 1 instance for the whole StdCouchDbConnector. This greatly reduces contention on ObjectMapper internal state synchronization when multiple thread are using it at the same time, which is often the case in a server side application.
in case of an update conflict, the response content should be consumed, in order to comply with HttpClient usage best practice for using keep alive
improvements about Connections releasing, work in progress
automatic detection of unclosed connections and unconsumed content, for proactive bug detection + fixed unconsumed content in QueryResultParser
better detection of end of stream
the connection should releaseConnection() on the HttpResponse it comes from
using a factory in order to be able to inject the desired behavior into the existing StdCouchDbConnector
added a public getter on the couchDbConnectorResponseHandlerFactory property, and using it instead of using the field
added comments on new class NonBlockingCouchDbConnectorResponseHandlerFactory