Disable dynamically added components in linear process

They should be disabled until the process is, itself, enabled, which is
almost certainly after it has been built!
Merge pull request #338 from mattdenner/disable_dynamically_added_components

Disable dynamically added components in linear process
Documentation update for linear-process
Building a labware component

Built component to display various types of labware using SVG.
Built component to dynamically display different types of labware.
Built a component that scans & displays labware.
Fixed up some event handlers that propogated their events.
Worked on composite event handlers, which isn't quite right.
Fixed up display of the SVG.
When no labware use the "unknown" labware for display.
Enable labelling to respond to the "focus" event.
Ensure that the labware scanning component handles "focus" events.
Pulled better code from presenter.js into standard_mappers.js.
Reuse standard mappers in the presenter code.
Use the labware display component in re-racking.
Support relabelling labware
Fix issue with process-choice erroring on all user barcodes