paypro: expose serialized payment request data on tx proposal.
paypro: add verifyPaymentRequest so we do not have to trust other copayers.
paypro: start verifying raw payment requests before signing.
Wallet: fix a potentially uncatchable error.
paypro: comments.
paypro: optimize verifyPaymentRequest check.
paypro: add tests for verifyPaymentRequest and signing tampered txs/prs.
paypro: sign an untampered payment request in tests.
paypro: fix verifyPaymentRequest. passing tests.
paypro: not necessary, but check merchant data in verifyPaymentRequest.
paypro: drop sign() calls in verify tests.
paypro: add separate tests for verifying abstract txp tx and pr.
paypro: tests - add more should() calls.
paypro: turn sig into hex string on txp.
paypro: remove logs. see #1043.
paypro: deal with no unspent outputs. see #1043.
put logs back in wallet model for payment protocol

This reverts commit e79d86d90625375e22ac2cbafb2c1f894a450bcf.
paypro: remove logs from tests. see #1043.
paypro: reorganize createPaymentTxSync.
paypro: extract addresses from server outputs and craft txs in this manner.