Add overmap special json

	new file:   overmap_specials.json
Selecting/verifying overmap special placement locations
First test (crashes)
Successful test run
Car stereos
Added stereos to item groups
Stereos need a cd to play
Fixed the wrong Id in item groups
Stereo saves
Fixed melee.json spacing getting messed up
better sounds for the sterep
Update flags/connections/placement code
Show Message every 5 turns
Merge remote-tracking branch 'origin/master' into stereo
Round out Json entries

Still missing crater, river, house.

Crater and river both require blob implementation, never seen random house spawn in game, so not sure what to do with it.
Testable version of new system with old specials
Use things other that CDs for music
Added rotation.  Still needs cleanup and json review
Dynamic spawns + BLOB pattern
Change how flags work, classic mode support