Merge pull request #4 from maran/reserved_balance

Per discussion on pull request 1

README.md

@@ -178,6 +178,8 @@ Say you want to publish an offer to sell 1.5 Mastercoins for 1000 bitcoins. Doin
 5. Time limit = 10 (10 blocks in which to send payment after counter-party accepts these terms) (8-bit unsigned integer, 1 byte)
 6. Minimum bitcoin transaction fee = 10,000,000 (require that the buyer pay a hefty 0.1 BTC transaction fee to the miner, discouraging fake offers) (64-bit unsigned integer, 8 bytes)
 
+The amount for sale will be reserved from the actual balance for this address much like any other exchange platform. For instance: If an address owns 100 MSC and it creates a "Selling Order" for 100 MSC this address's balance is now 0 MSC, reserving 100 MSC. Other outgoing Mastercoin transactions created while this order is still valid will be invalidated.
+
 ## Changing an Offer
 
 Say you decide you want to change the number of coins you are offering for sale, or change the asking price. Simply re-send the offer with the new details. If your change gets into the block chain before someone accepts your old offer, your offer has been updated.