Custom Track Tutorial/AST

Programs:
 * Any sound editor - for editing the sound
 * AstConverter by Anthe - for converting to and from .ast
 * Nintendo_AST_Creator by gheskett - for converting to .ast

Course music tips:
 * Final lap music is about 16% faster than the normal music.
 * The music repeats by itself, but the tools do allow you to set up a custom loop point.
 * When testing, make sure that the music and the in-game sounds are both audible.

Conversion to .ast: AstConverter by Anthe
 * 1) Open astConverter Metro.exe. A GUI should show up.
 * 2) Click the box on the left and select a valid audio file or drag a valid audio files onto the program.
 * 3) Set loop points, if wanted, on the boxes to the top right.
 * 4) Click on the button that says "Done. Press this button to start the conversion!" to convert the file.
 * 5) An .ast file with the same name as the input file should be input file's directory.

Nintendo AST Creator by gheskett  Simple Conversion
 * 1) Start with a 16-bit PCM .wav file
 * 2) Drag the .wav onto ASTCreate.exe
 * 3) A .ast file with the same filename as the input should appear in the directory of the input file.

Advanced Settings (Loop Mode)
 * 1) Start with a 16-bit PCM .wav file
 * 2) Create a .bat file that will run ASTCreate.exe with a dragged file. See the README for a list of all options.
 * 3) -s can be used to specify a loop start sample, and -e can be used to specify loop end sample / total number of samples. -n disables looping.
 * 4) An .ast file with the same filename as the input should appear in the directory of the input file, assuming a custom output file name was not set.

 GCKart.baa  In order to allow each course to have its own sound id, Yoshi2 edited GCKart.baa, found in Filesystem/AudioRes. The edited file can be found here. When using this file during testing, depending on the course being replaced, the .ast file may need to be edited to match up with the updated GCKart.baa. For testing on Dolphin via the .dol method or using GCRebuilder having this new .baa file is important for making sure that the track has the correct music playing.