Add new web3.js methods.

[ghost]

Added ftm methods:

getEvent,
getEventHeader,
getHeads,
getConsensusTime,
currentEpoch,
getEpochStats

Added sfc methods:

getValidationScore,
getOriginationScore,
getStakerPoI,
getRewardWeights,
getDowntime,
getStaker,
getStakerByAddress,
getStakers,
getDelegatorsOf,
getDelegator,
getDelegatorClaimedRewards,
getStakerClaimedRewards,
getStakerDelegatorsClaimedRewards

Added debug methods:

ttfReport,
validatorTimeDrifts,
validatorVersions