v1.4.0

This release brings some new features, improvements and bugfixes:

• Implement API for convenient asynchronous property get/set on the client-side
• Add support for FreeBSD systems (including support for basu implementation of sd-bus on non-systemd machines)
• Add support for direct, peer-to-peer connections
• Add option to create IConnection directly from an underlying sd_bus instance
• Some additional CMake-related and code bug fixes