NotePlayHandle: cleanups, header dependency reductions etc.

* do not include instrument_track.h in note_play_handle.h by making
  two functions non-inline
* renamed notePlayHandleVector / constNotePlayHandleVector to
  NotePlayHandleList / ConstNotePlayHandleList and changed typedef
  to QList (which has faster insert- and remove-operations).
* removed unused method willFinishThisPeriod()

Signed-off-by: Tobias Doerffel <tobias.doerffel@gmail.com>
(cherry picked from commit 08ea133aa2)

plugins/patman/patman.cpp

@@ -33,6 +33,7 @@
 #include "endian_handling.h"
 #include "engine.h"
 #include "gui_templates.h"
+#include "instrument_track.h"
 #include "note_play_handle.h"
 #include "pixmap_button.h"
 #include "song.h"

plugins/stk/mallets/mallets.cpp

@@ -34,6 +34,7 @@
 
 #include "engine.h"
 #include "gui_templates.h"
+#include "instrument_track.h"
 
 #undef SINGLE_SOURCE_COMPILE
 #include "embed.cpp"