v0.3.0

• Replace Apache Commons Hex class with minimal stub.
• Fix bugs in getValueIdByIdHash and getValueIdHashById.
• Copy listeners to prevent ConcurrentModificationException.
• Add an example that uses two EmDeviceEmulator instances.
• Rename Em1DeviceEmulator to EmDeviceEmulator.
• Add Em1DeviceEmulator and tests.
• Change BaseDeviceEmulator#update to return preferred sleep time.
• Add BaseDeviceEmulator class and tests.
• Add documentation to LittleEndianBuffer.
• Add TestablePropertyChangeListener.
• Add TestableConnection class.
• Add LittleEndianBuffer and tests.
• Add aggregator example.