don't panic during migration (filecoin-project#1598)

Use go-state-types proof types (filecoin-project#1597)

Use go-state-types proof types

Use new go-state-types state accessors (filecoin-project#1590)

* Use new go-state-types types

Update to go-ipld-cbor v0.0.6 (filecoin-project#1595)

Update to go-ipld-cbor v0.0.6 (filecoin-project#1594)

Update to go-ipld-cbor v0.0.6 (filecoin-project#1593)

Update to go-ipld-cbor v0.0.6 (filecoin-project#1592)

FIP-0027: Add JSON un/marshaler for DealLabel (filecoin-project#1591)

Zero out Sectors snapshot if no proofs have been submitted (filecoin-…

…project#1557)