Fix BROOKLYN-271: Avoiding object hashcode in entities' toString.

[kiuby88]

Fixing BROOKLYN-271
Avoiding object references in catalog ConfigKey cards, for example:

Last picture shows that default value of softwareProcess.lifecycleTasks config key does not contain the object hashcode @XXXXX. Then, objects toString methods are modified to avoid the hashcode.

[kiuby88]

@aledsage I think it should be better than apache/brooklyn-docs#68

[aledsage]

Thanks @kiuby88 - agreed this will improve the auto-generated entity docs (as per BROOKLYN-271).

In general, I like the toString to give more specifics about the object where possible. That is possible for some of these, and not for others. I'll comment on individual methods where I think we could include more.

[aledsage]

I'd go for the code below (using com.google.common.base.Objects):

@Override
public String toString() {
    return Objects.toStringHelper(this)
            .add("minDatapoints", minDatapoints)
            .add("timeToConsider",  timeToConsider)
            .add("maxProportionFailures", maxProportionFailures)
    .toString();
}

[kiuby88]

@aledsage, this tries to avoid the following entry in the catalog for JcloudsLocation.

I think this impl is enough, maybe ordering?

[aledsage]

LGTM, thanks @kiuby88 - merging. I incorrectly marked BROOKLYN-271 as resolved before this PR (and apache/brooklyn-library#38) were merged - sorry about that, and thanks for spotting!