Backporting to beta (#4118)

* Ignore get_price_info test by default. (#4112)

* Auto-detect hex encoded bytes in sha3 (#4108)

* Auto-detect hex encoded bytes in sha3

* Using types/isHex

* Removing unused imports

* Use binary chop to estimate gas accurately (#4100)

* Initial sketch.

* Building.

* Fix a few things.

* Fix issue, add tracing.

* Address grumbles

* Raise upper limit if needed

* Fix test.

* Fixing decoding API with signatures in names (#4125)

* Fix call/estimate_gas (#4121)

* Return 0 instead of error with out of gas on estimate_gas

* Fix stuff up.