Merge pull request #1 from undido/master

renamed blockchain.php to blockchain.class.php to indicate that it is a ...
Merge pull request #2 from undido/master

cleanup
Update blockchain.class.php
removed an extra curly bracket
Update createwallet.php
cleaned up strings. changed url to create wallet into a constant
made function getWalletBalance public
cleaned up commenting sort of... switched from get requests to post requests