Detect and report stray arguments

[smortex]

When a tool is run with stray arguments, they are silently ignored. This typically happen when a parameter must be repeated for each value (e.g. the --tag parameter is passed multiple values with --tag foo --tag bar and passing --tag foo bar only provide a single tag and the bar value is an argument that is silently ignored).

In order to avoid this issue, raise an error by default if stray arguments are found. It is possible to indicate that stray arguments are allowed by expilcitly saying so. In this case, the arguments are accessible using the #argv method.

[smortex]

There are inconsistencies within the riemann tools when passing parameters with multiple values:

• Some parameters accept a single value and can be repeated to pass multiple values. They have a singular name e.g. for adding tags:

  --tag foo --tag bar --tab baz
  

• Some parameters accept multiple values, but cannot be repeated. They have a plural name, e.g. for selecting only some devices with riemann-md:

  --devices md0 md1
  

We can adjust the code to accept both syntax, but this leave the issue that some parameters have a singular name and other a plural one.

I found that optimist gained the ability to have alternative parameters, but this has not been released yet:
ManageIQ/optimist#151

This could allow us to allow both singular and plural form 🤷 I have not yet made my mind. Do you have an opinion?

[jamtur01]

Seems reasonable.