r21 shell script

r21.sh

precondition: run from a song group folder.

Step 1: use mp3gain to normalize volume of all songs

Step 2: oggtools to convert mp3s to wav then to ogg

Step 3: run an error check to see if every song folder contains exactly one ".ogg"/".mp3" and one ".sm", print any failures and skip step 4 for those folders

Step 4: remove every file in the folders except for files ending in ".ogg" and ".sm"

Step 5: change all songlength tags to 1:45 (not sure how yet)