Fix F11/F12 split timing sync adjuster.

Docs/Changelog_sm5.txt

@@ -8,6 +8,10 @@ ________________________________________________________________________________
 StepMania 5.0 Preview 2 | 20110???
 --------------------------------------------------------------------------------
 
+2011/06/09
+* [ScreenSyncOverlay] Ensure that F11 / F12 work with all charts due to Split
+  Timing. [Wolfman2000]
+
 2011/06/08
 ----------
 * Any notes in a fake segment or warp segment are completely ignored for

src/ScreenSyncOverlay.cpp

@@ -253,7 +253,14 @@ bool ScreenSyncOverlay::OverlayInput( const InputEventPlus &input )
 
 			case ChangeSongOffset:
 				if( GAMESTATE->m_pCurSong != NULL )
+				{
 					GAMESTATE->m_pCurSong->m_SongTiming.m_fBeat0OffsetInSeconds += fDelta;
+					const vector<Steps *>& vpSteps = GAMESTATE->m_pCurSong->GetAllSteps();
+					FOREACH( Steps*, const_cast<vector<Steps *>&>(vpSteps), s )
+					{
+						(*s)->m_Timing.m_fBeat0OffsetInSeconds += fDelta;
+					}
+				}
 				break;
 			}
 		}