Use trusted setup from specs

[jtraglia]

This replaces the embedded trusted setup file with the one from the specs:

• https://github.com/ethereum/consensus-specs/blob/dev/presets/mainnet/trusted_setups/testing_trusted_setups.json

This did not work out of the box, because of the "0x" prefixes. I copied a helper function to do this where necessary.

[karalabe]

Note, the roots_of_unity fields are decimals, which will not be able to be represented in ,js. Go will be happy + thids lib ignores the, but the reason everything is hex everywhere is because some languanges are bad at big ints in json.