Provide a hint that more data exists when fetching resources

Currently when you `wsk action list` or trigger, rule, package, etc, you are not given any clue that more data exists. Yes the CLI lets you paginate easily, but if you aren't aware that more data exists, then you may not realize you are missing items. This hit me with `wsk package list` - I was convinced something was wrong when I couldn't find something and it was simply that I finally hit enough packages to hit the limit. The CLI doesn't necessarily need to say how many records exist (although that would be nice), but should provide a clue that the result was truncated.