While this PR primarily encompasses changes pertaining to enabling support for using mode 3 of cvmfsexec whenever possible, it also contains an updated way to check for script duplication.
Closing this PR since the upstream branch was outdated at the time of creating this draft PR, which resulted in a huge number of changes/files to be reviewed which are merged with the upstream master.
While this PR primarily encompasses changes pertaining to enabling support for using mode 3 of cvmfsexec whenever possible, it also contains an updated way to check for script duplication.