[Song] add IsDisplayBpmRandom Lua binding

Docs/Changelog_sm-ssc.txt

@@ -10,9 +10,13 @@ supported but exist anyways.)
 _____________________________________________________________________________
 
 ================================================================================
-sm-ssc v1.2.1 | 2011011?
+sm-ssc v1.2.1 | 201102??
 --------------------------------------------------------------------------------
 
+20110201
+--------
+* [Song] Added IsDisplayBpmRandom Lua binding. [AJ]
+
 20110130
 --------
 * [ScreenSelectMaster] Only run cursor commands on players if they exist. [AJ]

src/Song.cpp

@@ -1553,6 +1553,11 @@ public:
 		lua_pushboolean( L, temp.BpmIsConstant() );
 		return 1;
 	}
+	static int IsDisplayBpmRandom( T* p, lua_State *L )
+	{
+		lua_pushboolean( L, p->m_DisplayBPMType == Song::DISPLAY_RANDOM );
+		return 1;
+	}
 
 	LunaSong()
 	{
@@ -1601,6 +1606,7 @@ public:
 		ADD_METHOD( GetDisplayBpms );
 		ADD_METHOD( IsDisplayBpmSecret );
 		ADD_METHOD( IsDisplayBpmConstant );
+		ADD_METHOD( IsDisplayBpmRandom );
 	}   
 };