v2.0.0 IAO

IAOLinearVesting
25% of tokens are released at the endBlock of this IAO and the other 75% are distributed linearly between the endBlock and vestingEndBlock.

• vestingEndBlock is set to define when all of the offering tokens will be 100% unlocked.
• A refund of stakeTokens when there is an oversubscription of the IAO will be given on the first harvest
• offeringTokens are sent to users based on the number of vesting blocks that have passed since the end of the IAO. 25% is released on the first harvest along with a refund for over-subscriptions

What's Changed

• Updates based on most recent audit by @DeFiFoFum in #11
• IAO Linear Vesting by @DeFiFoFum in #10

Full Changelog: v1.0.0...v2.0.0