Push back the coins - no withdraw needed

[martinkrung]

Allow to give an extra fee on bid to automatically get the token pushed back to the committing address - no stuck liquidity in the contract

This also could be paid by the IDO party?!

Is it possible to let bidders pay for this in advance?

Could be paid by the buyer on biding, mint gastoken owned by the contract, and use the gastoken to pay for the push back.

pro:

• speed up innovation cycle
• lower support cost by not have to maintain "no withdraw" user years later
• lower infrastructure cost by not having to maintain old interfaces
• contract could be deleted and gas redeemed?

con:

• Instant liquidity of all token hit the market, so temptation to sell may be higher?

FixedPrice had/has this and still has by allowing anyone to withdraw token for a purchase