In-process INode for applications

INode interface is Bytecoin's high-level API library that provides network node functionality. Its in-process implementation allows to launch an instance of Bytecoin daemon inside any C++ application. As an example, it allows Bytecoin Wallet to run a native network node. What's more, if you have a local Bytecoin daemon running, INode will connect to it rather than create a new in-app instance. This update marks the start of Bytecoin lightweight wallet development, a long-awaited feature in CryptoNote ecosystem.