Terminology used in Command implementations

[michael]

I think these are a bit confusing at the moment.

Currently used terminology:

• params (passed in via ctor), they are specified at the configurator level. this is all static stuff
• props (passed in for getCommandState and execute) and contain documentSession, selectionState, surface, selection for getCommandState. For execute the previously computed commandstate is merged into props.
• context (provide access to app-specific childContexts, core tools don't use context)

Suggested terminology:

• config (relates it better to the configurator level and it's static nature)
• params (no confusion with props which are used in components)
• context (as is)

Instead of merging commandStates into params as done right now, I would provide commandState as an individual key. This would require some refactoring, but maybe worth to do that now as we can then freeze the command API for 1.0.

Thoughts?