No warning for unused options using keyval approach

[josephwright]

Brief outline of the bug

As title: the behaviour is inconsistent with classical option processing.

Minimal example showing the bug

\RequirePackage{latexbug}
\begin{filecontents}[overwrite]{myclass.cls}
\ProvidesClass{myclass}[9999/12/31]
\LoadClass{minimal}
\DeclareKeys{foo .store = \myclassfoo,foo .default:n = {},baz .store=\myclassbaz}
\ProcessKeyOptions
\end{filecontents}
\documentclass[foo,bar,baz=foo]{myclass}
\begin{document}
\end{document}

Log file (required) and possibly PDF file

test.log

[Skillmon]

Additionally, used/known options aren't removed from the unused options list for a class file:

\RequirePackage{latexbug}
\begin{filecontents}[overwrite]{myclass.cls}
\ProvidesClass{myclass}[9999/12/31]
\LoadClassWithOptions{article}
\DeclareKeys{foo .store = \myclassfoo,foo .default:n = {},baz .store=\myclassbaz}
\ProcessKeyOptions
\end{filecontents}
\documentclass[foo,bar,baz=foo]{myclass}
\begin{document}
\end{document}

throws warnings about unused global options for both foo and baz.

[josephwright]

I have pushed an initial fix. @Skillmon asks if this should include zapping spaces in the unused option name: I am not so sure so I've not done that yet. Thoughts welcome.