Correct tax and sent amount on /money pay

/money pay now reports amount of tax and money sent correctly.

Example: value 10; tax 2
Before: "Transaction tax deducted from your account: 12 emeralds. Sent 12 emeralds to Notch"
Now: "Transaction tax deducted from your account: 2 emeralds. Sent 10 emeralds to Notch"

On insufficient funds it still correctly reports value+tax as the required amount.
Merge pull request #107 from noidexe/patch-1

Correct tax and sent amount on /money pay