Separated the shortcut methods, d(), dc(), etc to a separate module. This makes them easier to use in other situations (and also you can reload the module if you need to make changes to it).
Minor changes to api shortcuts docstrings.
Added functions to center selected strands on screen and follow the selected strand's connection (5p/3p). Including neat animated translation :)
Created cadnano_api.centerOnScenePos, and re-wrote centerOnSelected to use this rather than the flaky view.centerOn() native. Also move_active_baseindex_to_strand() to move slider in pathview. Other than that, mostly comments/docstrings and minor additions.
Added docstring to Preferences view and removed excess whitespaces (editor auto).