Nrfutil

Features
* Security Updates to Zigbee External Application and Boot Validation (175)
* Generate Zigbee production config binary (167)

Bugfixes
* Improper handling of trigger requests during Thread DFU (169)

Note
The major version number was increased in this release is because of a change in DFU protocol, and the need to differentiate between SDK versions. More info in [readme/versions](https://github.com/NordicSemiconductor/pc-nrfutil#versions).

Features
* Add Zigbee DFU image support (experimental) (161)
* Update sd-req list (156)
* Update pc-ble-driver-py version

Note
The reason for the major version change of this release is because of a change in DFU protocol, and the need to differentiate between SDK versions. After SDK 15.1 release, there is an additional page used in order to backup Bootloader DFU settings during value updates. nrfutil introduces a new flag, --no-backup, for compatibility with SDK version 12.0 to 15.0.
More info in [readme](https://github.com/NordicSemiconductor/pc-nrfutil#settings).

Features

* Application valid flag not set when generating settings without app (140)
* Updated firmware IDs (141)
* Updated text for dfu bootloader version (142)
* Detecting and warning user if this is a legacy version of nrfutil (143)
* Updated unit tests (136, 144)

Features

* Ultra-verbosity for showing all bytes sent/received over serial (121)
* Update error string for invalid signature in init packet (122)
* Add start address option for bootloader settings (128)
* Allow customizing delay between DFU connections (129)
* Add info about MSD in certain error scenarios (130)

Features

* Added `usb_serial` DFU mode
* Added NRF52810 and NRF52QFAB families (for bootloader settings generation)
* Added Thread multicast DFU support
* Allow creating DFU packages without a cryptographic signature
* Updated SoftDevice IDs for S132
* Expanded some of the inline help

Bugfixes

* Upgrade pc-ble-driver-py dependency to v0.11.3. This comes with connectivity firmware v1.2.0 that fixes an issue with buffer sizes related to ATT MTU and serialization. (https://github.com/NordicSemiconductor/pc-ble-driver/pull/47)
* Fix issue where service changed characteristic was enabled when not present (92)