Remove non-trading AU sites

-spendbitcoins (re-directs to localbitcoins.com)
-www.bitcointrader.com.au (defunct)
-bitxoin.com (defunct)
-buybitcoinaustralia.com (does not appear to be trading)
-www.Bitcoin4Australia.com (does not appear to be trading)
Merge pull request #133 from andrewbtc/patch-2

Remove non-trading AU sites