EOS ICO: Update to add buyer protections

@dan just committed an update to the draft ICO contract on Github.

Here are the described changes:

1. Buyer can require that the payment apply to the intended day or
transaction will fail returning funds.
2. Buyer can require that after adding his funds the total funds sent in
for the day is below a particular threshold.
With these two changes a buyer submitting at the last second has

assurance that miners will not move his order to the next day and he has

assurance that if the effective price goes above his target price

before his funds are applied then it will not apply.
This does not protect a buyer from having the price go above his target

price after his funds are applied.
Unfortunately, buyer pays gas prices even if the transaction fails.

What are everyone's thoughts?