Added method for writing #SONGSELECT entries
Added new boolean flag bUseSongSelect to CourseEntry
Added new function StringToSongSort()
Renamed "LIVES" to "GAINLIVES"
Added new m_sSongName property to Song class
Slight refactor in Song::LoadSongFromDir() to set m_sSongName
Implemented the basics of #SONGSELECT course parameter
(Fixes a crash that can occur with some songs if functions like TimingData::NoteRowToMeasureAndBeat are called for rows that don't have a time signature defined)