[Add] Allow missions to interact with music subsystem.

dat/missions/emp_collective05.lua

@@ -174,6 +174,10 @@ function final_talk()
     -- ESS Trinity becomes collective now.
     trinity:setFaction("Collective")
 
+    -- Some music.
+    music.load("galacticbattle")
+    music.play()
+
     final_fight = 3
     misn.timerStart("final_talk", rnd.int(4000, 5000))
   else if final_fight == 3 then

src/misn_lua.c

@@ -22,6 +22,7 @@
 #include "player.h"
 #include "ltime.h"
 #include "xml.h"
+#include "music.h"
 #include "misn_lua.h"
 
 /* Similar to lua vars, but with less variety. */
@@ -167,6 +168,7 @@ int misn_loadLibs(lua_State* L) {
   lua_loadTk(L);
   lua_loadHook(L);
   lua_loadPilot(L, 0);
+  lua_loadMusic(L, 0);
   return 0;
 }