Update 1.2.3f

Editor
- Fixed a bug where deleting all notes and then saving when using an audio mode caused the old notes to reappear.
- Narrate selecting all with Ctrl-A.
- Added commands to move the sample under the cursor up or down by your cursor resolution.  Use ctrl-shift-up and ctrl-shift-down.
- Added a new version of the track spline which is easier to edit.  Existing tracks will still use the old version until you upgrade using the Use Latest Spline Version option in the Edit Track menu.
- Changed the spline editor controls for constraining translations:
B to constrain to backwards on the spline.
F to constrain to forwards on the spline.
U to constrain to the node's up vector.
Shift-T to constrain to the vector from the control point to the track.
D to disable constraints.
- In the spline editor, the period key now moves the camera to the selected point.
- Fixed a bug where the world saturation setting was not saving properly.

- Fixed a bug where the game volume could be lowered in the menus due to audio cues 1 mode's volume changes.