Handle return code of onecmd_plus_hooks

[kmvanbrunt]

There are a few cases in cmd2 where onecmd_plus_hooks() returns True, which means stop the command loop, but stop is not passed up. Evaluate these cases and determine if stop should be handled.

[teto]

any code to test :p ? looking forward to this

[tleonhardt]

@teto
There is some code on the script_refactor branch which I believe addresses this issue. @kmvanbrunt isn't done with it yet. But I believe he is done with this part of it, so you should be able to test that if you like and leave any feedback you have here.