Remove dependency on dktactics/fol and add Coq import
Depending on dktactics makes writing the interoperability layer hard because most types in dktactics are not definable. Moreover, this removes dependency on Dedukti v2.6 (featuring injective symbols). When the transfer tactic will be called, it will not know about the rule [a,b] term (arr a b) --> term a -> term b.
Showing with 426 additions and 894 deletions