refactoring of RelayServer
Merge branch 'master' of https://github.com/bitcoin-solutions/multibit-hardware

Conflicts:
	core/src/main/java/org/multibit/hd/hardware/core/wallets/HardwareWallet.java
	trezor/src/main/java/org/multibit/hd/hardware/trezor/AbstractTrezorHardwareWallet.java
	trezor/src/main/java/org/multibit/hd/hardware/trezor/relay/RelayServer.java
	trezor/src/main/java/org/multibit/hd/hardware/trezor/shield/TrezorShieldUsbHardwareWallet.java
	trezor/src/main/java/org/multibit/hd/hardware/trezor/v1/TrezorV1UsbHardwareWallet.java