remove non-piraha parser from CST

[Roland Haas]

In the Turing release announcements: http://einsteintoolkit.org/about/releases/ET_2020_05_announcement.html we are deprecating the non-Piraha parser (since it will not be updated to handle the READS / WRITES in the same manner the Piraha based parser will be).

It should thus be removed from the code.

[Roland Haas]

This will render #2088 obsolete.

[Steven R. Brandt]

@Roland Haas https://bitbucket.org/cactuscode/cactus/pull-requests/105/this-pr-attempts-to-remove-the-old-perl

[Roland Haas]

There seem to be more opportunities to remove now dead code:

• some of the parsers called subroutines that are no longer needed
• the parser comparison routine can be removed

With there being only a single data structure it should no longer be called $foo1 but just $foo.

Comments in the pull request show individual instances of these, though there may be some that I missed.

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[Roland Haas]

Please squash the commits and use a subject line that starts with “Cactus: “.

Please apply.

[Roland Haas]

Applied as git hash 2e0fc750 "Cactus: This PR removes the old Perl-based CCL parser." of cactus