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
Add color support for messages

This commit contains some dummy message functions (_type).
They are intended to be removed in a later commit
Overload message functions

… and get rid of those ugly “_type” things
Overload player.cpp wrappers around add_msg
Ensure new game_messages have always a type.
Change enum game_message_type
Fixed melee.json spacing getting messed up
Put most game messages (add_msg …) into an appropriate category
Make new NPC wrapper functions around add_msg (with type)
Colorize melee battle messages
Colorize death and guilt messages
Colorize mutation messages