A lot of screens have TweenOffScreen functions; SWME has that, and it's not

virtual, so the names are clashing and confusing.  This should probably just
be virtual.  As an incremental step to that, rename all derived TweenOnScreen
and TweenOffScreen screen functions to TweenOursOnScreen and
TweenOursOffScreen.

stepmania/src/ScreenSelectGroup.cpp

@@ -130,7 +130,7 @@ void ScreenSelectGroup::Init()
 	SOUND->PlayMusic( THEME->GetPathS("ScreenSelectGroup","music") );
 
 	AfterChange();
-	TweenOnScreen();
+	TweenOursOnScreen();
 	m_GroupList.SetSelection(0);
 
 	this->SortByDrawOrder();
@@ -227,7 +227,7 @@ void ScreenSelectGroup::MenuStart( PlayerNumber pn )
         SOUND->PlayOnceFromAnnouncer( "select group comment general" );
 
 
-	TweenOffScreen();
+	TweenOursOffScreen();
 	this->PostScreenMessage( SM_BeginFadingOut, SLEEP_AFTER_TWEEN_OFF_SECONDS );
 }
 
@@ -236,7 +236,7 @@ void ScreenSelectGroup::MenuBack( PlayerNumber pn )
 	Cancel( SM_GoToPrevScreen );
 }
 
-void ScreenSelectGroup::TweenOffScreen()
+void ScreenSelectGroup::TweenOursOffScreen()
 {
 	OFF_COMMAND( m_sprExplanation );
 	OFF_COMMAND( m_sprFrame );
@@ -249,7 +249,7 @@ void ScreenSelectGroup::TweenOffScreen()
 	m_GroupList.TweenOffScreen();
 }
 
-void ScreenSelectGroup::TweenOnScreen() 
+void ScreenSelectGroup::TweenOursOnScreen() 
 {
 	SET_XY_AND_ON_COMMAND( m_sprExplanation );
 	SET_XY_AND_ON_COMMAND( m_sprFrame );