Deprecate Lua's HasNegativeBPMs().

Use HasWarps() instead.

Hmm...is there a way to mark the XML with a deprecated tag?

src/TimingData.cpp

@@ -1746,7 +1746,7 @@ public:
 		LuaHelpers::CreateTableFromArray(fBPMs, L);
 		return 1;
 	}
-	static int HasNegativeBPMs( T* p, lua_State *L )		{ lua_pushboolean(L, p->m_bHasNegativeBpms); return 1; }
+	static int HasNegativeBPMs( T* p, lua_State *L )		{ lua_pushboolean(L, p->HasWarps()); return 1; }
 	// formerly in Song.cpp in sm-ssc private beta 1.x:
 	static int GetBPMAtBeat( T* p, lua_State *L )		{ lua_pushnumber(L, p->GetBPMAtBeat(FArg(1))); return 1; }
 	static int GetBeatFromElapsedTime( T* p, lua_State *L )	{ lua_pushnumber(L, p->GetBeatFromElapsedTime(FArg(1))); return 1; }