Fixed possible left-over in ProvisioningManager line 188. please check.
Introduced PluginVisitor to reduce code duplication.
Use PluginVisitor to discover options.
You will observe a delay when completing options.
Completion is minimal, only propose the option names, no handling of value (hasValue, ...).
InstallCommand is the only one to benefit from the --plugins-options for now, other commands (Diff/Upgrade) have some hard-coded options that could need some revisit to comply with plugins-options.