Added revalidation scheme to NoteData's all_tracks_iterator

Performing a transform on NoteData invalidates all iterators into it.  Player stores iterators into the NoteData in the form of several all_tracks_iterators.  During gameplay in a course that uses a transform on the second song, StepMania would crash on starting the second song because the iterators has been invalidated by the transformation.  This adds a way for a NoteData to update all the all_tracks_iterators that refer to it to make them valid again, and changes all transforming functions in NoteDataUtil to tell the NoteData to revalidate after the transform is complete.
Getting Started from ITG2 is a good course to test with.

#COURSE:Getting Started
#METER:REGULAR:4;
#METER:DIFFICULT:7;
 
#MODS:
  TIME=00.00:END=101.21:MODS=Little, NoHolds, NoMines, NoJumps:  
  TIME=14.33:END=28.66:MODS=20% Beat:
  TIME=42.99:END=57.31:MODS=20% Beat:
  TIME=71.64:END=85.97:MODS=30% Boost: 
#SONG:Baby Baby:Easy:;

#MODS:
  TIME=00.00:END=99.85:MODS=Little, NoHolds, NoMines:
  TIME=14.67:END=30.09:MODS=50% Bumpy:
  TIME=43.81:END=57.52:MODS=40% Wave:
  TIME=71.24:END=84.95:MODS=40% Mini:
  TIME=98.67:END=105.52:MODS=40% Beat:
#SONG:My Life is so Crazy:Easy:; 

#MODS:
  TIME=00.00:END=99.85:MODS=NoJumps, NoMines:
  TIME=16.24:END=30.68:MODS=40% Mini:
  TIME=45.11:END=59.55:MODS=40% Beat:
  TIME=58.65:END=66.32:MODS=2x:
  TIME=73.98:END=88.42:MODS=25% Stealth:
  TIME=88.42:END=102.41:MODS=40% Mini:
#SONG:The Message:Medium:;

#MODS:
  TIME=00.00:END=99.85:MODS=NoMines:
  TIME=23.10:END=44.43:MODS=50% Hallway:
  TIME=44.43:END=58.65:MODS=20% Expand:
  TIME=58.65:END=72.88:MODS=50% Distant:
  TIME=72.88:END=81.76:MODS=40% Mini:
  TIME=81.76:END=95.99:MODS=40% Wave:
#SONG:Baby Don't You Want Me:Medium:;