See: https://github.com/tendermint/tendermint/pull/1815/files#r205110595

We should refactor lite/* after launch, to save components of the full commit rather than the whole full commit itself. This refactor should start with an ADR that describes the new interfaces.

Post-launch, as it doesn't affect the chain itself so upgrading is relatively easy.

Probably also should include ADR for InquiringCertifier (to be renamed as DynamicVerifier).