Allow editing #DISPLAYBPM traits in the editor.

Look in Edit Song Info to find it.

src/Song.h

@@ -35,6 +35,15 @@ enum BackgroundLayer
 	NUM_BackgroundLayer,
 	BACKGROUND_LAYER_Invalid
 };
+
+/** @brief The different ways of displaying the BPM. */
+enum DisplayBPM
+{
+	DISPLAY_BPM_ACTUAL, /**< Display the song's actual BPM. */
+	DISPLAY_BPM_SPECIFIED, /**< Display a specified value or values. */
+	DISPLAY_BPM_RANDOM /**< Display a random selection of BPMs. */
+};
+
 /** @brief A custom foreach loop for the different background layers. */
 #define FOREACH_BackgroundLayer( bl ) FOREACH_ENUM( BackgroundLayer, bl )
 
@@ -222,7 +231,7 @@ public:
 	float	m_fSpecifiedLastBeat;	// specified last beat of the song
 	float	m_fMusicSampleStartSeconds;
 	float	m_fMusicSampleLengthSeconds;
-	enum { DISPLAY_ACTUAL, DISPLAY_SPECIFIED, DISPLAY_RANDOM } m_DisplayBPMType;
+	DisplayBPM m_DisplayBPMType;
 	float	m_fSpecifiedBPMMin;
 	float	m_fSpecifiedBPMMax;	// if a range, then Min != Max