my take on not exposing secrets

the idea is the default behavior is to not expose secrets.  There are times, though, when it is a handy feature to get the app itself to write out a compete config file.  

this PR adds the ```--admin.expose_secrets``` command line option and adds a ```secret``` attribute to the Options class.  If ```--admin.expose_secrets``` is NOT on the command line, then ```--admin.print_conf```, ```--admin.dump_conf``` & ```--help``` will always an Option's value as "****************" if that Option has the attribute ```secret == True```.

won't likely slow it down noticably at all.  it is still of an O(n) complexity where n is the number of options in an application.  Even in the case of our most complicated app (processor) that's only 200 items in the list.   Plus, this code only gets used during output: writing the Help message or a configuration file.  That code is not encountered when just running an app.