Plonk/PP : change v_map − Fixes #109

v_map does now only contains polynomials that must be composed, and all polynomial that are not in v_map are composed with X.

KZG query is now deduced from h_map (for the prover) and from the identities (for the verifier) ; if a polynomial is in h_map and not in identities it will fail because the queries have to be the same.