Added stub allowing to development without LCD.
Optionally log both successful and failed transactions to CSV file (datetime,OK if success,$amount,btc address,btc amount).
Catch both too big and too small amounts (btc spam).
Updated docs on the CSV log
Fixed markup.
Clear GUI properly in case of bad amount.
Merge pull request #3 from jurov/master

Transaction logging and check for too small/big amounts.