Use DXX_ALWAYS_ERROR_FUNCTION for printf check

Enable printf check without relying on embedded compound statements.
Extend sconf force support

Allow forcing a test to succeed without changing flags.
Use find_if to traverse key_properties
Refactor kick_player out of multi_send_message_end
Simplify audio CD discovery
Reduce header includes of physfsx.h
Use unique_ptr to manage fonts
Throw on too many fonts open
Use array<> for ab_load
Fix crash parsing bad mission file
Use unique_ptr<> for briefing
Use unique_ptr for Current_mission
Use unique_ptr to manage grs_bitmap
Use unique_ptr to manage sub bitmaps
Use unique_ptr for light_array