Add "goal" as a type recognized by scripted sexps. Also add `mn.Goals` as a collection to complement `mn.Events` and move the goal type to goal.cpp and goal.h to match event.cpp and event.h. The new `mn.Goals` collection contains the same data as the existing `Objectives` collection in the briefing UI library, so the latter could be deprecated.
1) Upgrade the pilot file code to correctly save flags whether entries are added *or* removed
2) Make the tech-db/tech-db-multi ship flag handling consistent
3) Add scripting support for intel entries
4) Add scripting support for adding and removing entries from the tech room
5) Minor cleanup
This maintains the type information which can be used for enforce
const-correctness and also for implementing more advanced ways of
handling the type information.
Goober5000