Fix Level and Preferred Sorts to account for a song being in multiple sections

This commit properly returns you to the correct pack when leaving a folder or returning from another screen.
This is achieved by returning you to your last open section. Previously behavior searched for the first instance of the song in your sort and put you in that section.

src/WheelBase.cpp

@@ -290,12 +290,14 @@ bool WheelBase::Select()	// return true if this selection can end the screen
 			RString sThisItemSectionName = m_CurWheelItemData[m_iSelection]->m_sText;
 			if( m_sExpandedSectionName == sThisItemSectionName ) // already expanded
 			{
+				GAMESTATE->sLastOpenSection = sThisItemSectionName; // remember this section
 				SetOpenSection( "" ); // collapse it
 				m_soundCollapse.Play(true);
 			}
 			else // already collapsed
 			{
 				SetOpenSection( sThisItemSectionName ); // expand it
+				GAMESTATE->sLastOpenSection = sThisItemSectionName; // remember this section
 				m_soundExpand.Play(true);
 			}
 		}