Misc setoids lemmas and tweaks for maps and option
- Add lemmas
map_singleton_equiv_injandmap_fmap_equiv_inj. - Add lemma
option_fmap_equiv_inj. - Add
Propers for maps, and generalize existing ones. Add tests to check that the old ones can be derived. - Add lemma
map_equiv_lookup_r. - Add lemma
map_equiv_iff.
Also, rename instances option_mbind_proper → option_bind_proper and option_mjoin_proper → option_join_proper to be consistent with similar instances for sets and lists.