Small fixes.

[zweigraf]

• Eliminates warnings in the generated code by using special handling for methods that would result in a Void return.
• Fix crash when address does respond to a certain function (e.g. if address is not a HumanStandardToken decoding the0x return data for Name function would crash).
• Revert back to official CryptoSwift.
• Improve testing guide.
• Add unwrap() to some types to allow for getting the wrapped value out of the solidity wrapper.