Release of BlueZ 5.50

This release contains several fixes to GATT and Mesh support. Some notable new features include a ‘node-reset’ command to meshctl, a new btmon-logger daemon to perform logging on unattended systems, and a new general discoverable property in the advertising D-Bus API.

This release also contains numerous build fixes for GCC 8, making it fully buildable e.g. on Fedora 28.