Export more entities and entity properties

[oznogon]

Expand what's exported by the "Copy scenario"/"Copy selected" buttons on the GM screen.

• Consolidate common entity properties to export functions.
  • Expand Basic export; add callsign, scan_state changes
  • Expand ship changes export: add propulsion, beam mounts, docking port/bay properties, AI orders
  • Add type-specific exports: API functions to populate properties specific to that type of entity
• Reimplement utils.lua isObjectType() checks for getEntityExportString().
• Export Lua API functions for more entity types.
  • VisualAsteroid(): basic export
  • Planet(): type-specific size, textures, distance from plane, spin
  • WormHole(): type-specific gravity, target
  • SupplyDrop(): type-specific energy and weapon supplies
  • WarpJammer(): type-specific range
  • ScanProbe(): type-specific lifetime, move_to speed
  • Artifact(): type-specific spin

Limitations:

• Doesn't capture internally docked ships

Output before: master.lua

Output after: expand.lua