Fix command substitution and error handling stuff related to get_accuraterip_checksum_of_singletrack_or_die:
- Quote the command substitution to prevent globbing etc.
- Add missing error handling for sed
- Don't use exit within the function because it is used in command substitution and therefore we cannot exit because we are in a subshell. Fix the callers to have proper error handling.
- Remove the "_or_die" from the function name because it cannot exit
Quote command substitution to prevent globbing etc.
Add missing error handling for command substitution
Add code & TODO for using the bash options errexit/errtrace. Those would make the script exit upon any command in the script having error exit status. The code is not enabled yet because there are some cases in the script which trigger errexit unnecessarily.