Further Group enhancements.

- Adjust the variable scope of group attributes
- Remove the now redundant GroupBannerPaths vector and replace its usage.
- Migrate ini loading logic to Group class
- Better clarity on comments for Group
- Remove GetTotalSongs in favor of GetSongs.
- Add Year as a value to Group.ini
- Ensure new group and song maps are cleared properly when freeing songs

src/MusicWheel.cpp

@@ -758,10 +758,8 @@ void MusicWheel::BuildWheelItemDatas( std::vector<MusicWheelItemData *> &arrayWh
 						Group* pGroup = pSong->GetGroup();
 						if( bUseSections )
 						{
-							RString sThisSection = pSong->GetGroup()->m_sSortTitle;
-							if (pGroup->m_bHasGroupIni) {
-								sThisSection = pGroup->m_sGroupName;
-							}
+							RString sThisSection = pSong->GetGroup()->GetSortTitle();
+
 							if( sThisSection != sLastSection )
 							{
 								int iSectionCount = 0;