Create a workflow for style updates that may involve upstream processing

[jeffreyameyer]

[Note: this is more for internal instruction / discussion than a specific task]

Many style changes cannot be accomplished in the stylesheet alone and depend on the availability of data that already exists (e.g. tags) or that needs to be generated (e.g. derived tags or spatial constructs).

So, when end users or our cartographers present requests for styling changes, workplans for tickets should include breakouts for:

• [ ] addition of existing tag data to vector layers (if needed)
• [ ] generation of spatial derivatives of existing data (if needed)
• [ ] generation of tag derivatives (if needed)
• [ ] stylesheet changes

A use case example of this is shown in this comment from #481 [Render names according to the language the user is using?].

Specific examples of each of these items are as follows:

• Adding additional tag data into our vector layers:
  • adding rail-centric tags,
  • adding ferry lines
• Generation of spatial derivatives:
  • Creation of polygon centroids for label points: #195
  • Removal of coastlines from boundary polygons
• Generation of tag derivatives:
  • Localization
  • Augmentation / improvement of data: See discussion of data-driven scale rank in #544.
  • Standardization / formatting