Feature/more launch buttons and dropdowns

[danfunk]

There is a complete list of events in the README, and everything has an example in app.json

• Json files and DMN Files are now selection lists, not a text field.
• Launch Editor button for Call Activity
• Launch Editor button for Json Files
• Launch Editor button for DMN Files
• Standardized all event names (yes, they all changed)
• Removed tons of duplicated code.
• Standardized the moddle names -- so if it's in the body of a tag, it is always referenced as ".value"