misc: add new minimal thydeps script for Isabelle2018

misc: retire broken thydeps script

Removes all trailing whitespaces

fix thydeps parser to handle % in keyword syntax

thydeps: support Perl version 5.24

Perl version 5.24 no longer allows use of $_ as a lexical variable.

thydeps: silence perl warnings; handle nested comments

thydeps: support expanding variables in theory imports

See the updated documentation.

Fix up c-parser and autocorres for AutoCorres 1.2 release.

Import release snapshot.