Introduce boolean nostream parameter to StatsCmd #1278

In order to use StatsCmd in not streaming style I would like to see parameter in StatsCmd that could help to execute request to Docker stats command with "stream=0" parameter.

This could be simply achieved by introducing methods

@CheckForNull
Boolean getNoStream();
StatsCmd withNoStream(Boolean noStream);

in StatsCmd.java

And adding

if (isTrue(command.getNoStream())) {
webTarget = webTarget.queryParam("stream", "0");
}

to both StatsCmdExec.java in com.github.dockerjava.jaxrs and com.github.dockerjava.core.exec packages.

This also can help to resolve
#971
#375

I can make a pull request for this if it is preferable=)