Release of BlueZ 5.40

This is mostly a bug fix release fixing issues with GATT, paired devices and connection handling (particularly for accepting connections through the Profile D-Bus interface).

One new feature is the ability to use btmon for reading HCI logs from a TTY device. Right now the creation of this kind of logs is available with Zephyr in the form of a special console logging mode (more information available here). The format of the protocol is a slight modification of what btmon normally receives from the kernel monitor sockets, and is documented in doc/btsnoop.txt).