Decide which sUtra bars which sUtras

#583
Both frontend and CLI has this facility.
The intermediate files are stored in sutrarelations folder.
understandsutra.sh is the CLI for this utility.
scripts/sutrarelationdisplay.php is the frontend facility.
Frontend facility presumes that you have already run the tiGanta.php code without any sUtra suppressed, and then with some sUtra suppressed.