fix, properly free filter definitions upon freeing echs-mod smobs

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
Merge branch 'core/echs-lisp' into next

* core/echs-lisp:
  fix, properly free filter definitions upon freeing echs-mod smobs
minor, rename fltdef's opener, closer and psetter

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
minor, adapt echse.c, echs-lisp.c and echs-filter.c to renamings in fltdef.h

Signed-off-by: Sebastian Freundt <freundt@ga-group.nl>
Merge branch 'code/hygiene' into next

* code/hygiene:
  minor, adapt echse.c, echs-lisp.c and echs-filter.c to renamings in fltdef.h
  minor, rename fltdef's opener, closer and psetter