Ongoing: Look for opportunities to simplify and reorganize code

[jsoules]

Action items include:

• More intuitive layout of components
• Reducing parameter lists for components with large numbers of parameters
• Centralizing logic for looking up facts from the data dictionary
  • In particular, converting between toggleable values, value lists, positive boolean selections, etc.--basically everything done for the plotLegend component--is unclear and spread across multiple sources. Come up with a consistent place for this.
• Update index files used to simplify imports across the app