liquidationInitiator fallback revert can block purchaseSignerBondsAtAuction

[NicholasDotSol]

during purchaseSignerBondsAtAuction, Instead of receiving a share of the funds the liquidationInitiator can decide to intentionally reject the funds by raising an exception causing initiator.transfer(contractEthBalance) to throw, blocking the auction and forcing the liquidation to fail. The deposit will stay in one of the *_liquidation_in_progress states.

• use address.send instead instead of address.transfer