Correcting some comments

Signed-off-by: Dsyko <dsykora@gmail.com>
Adding new Class TradeController, which will make decisions about trading
bitcoin based on market conditions. Cleaned up MtGox.py a little

Signed-off-by: Dsyko <dsykora@gmail.com>
Adding HTTP error catching decorator function

Signed-off-by: Dsyko <dsykora@gmail.com>