Bonding taxes

[mrsmkl]

Something has to be changed here, otherwise the task giver can withdraw or bond the deposit, and the solver cannot register for the task.

From comments in the code:
LOOK AT: May be some problem if tax amount is also not bonded but still submitted through makeDeposit. For example, if the task giver decides to bond the deposit and the tax can not be collected. Perhaps another bonding structure to escrow the taxes.

Perhaps the tax should be burned at the same time as reward is paid. Also there doesn't seem to be a way to return the reward if there are no solvers.