UHD-3.12.0.0

• N3x0: Add White Rabbit support, add N300 support, standard BIST includes fan, fix issue with 1GigE, switch to 2 radio blocks with 2 channels each, upgrade TDC to version 2.0, fix issue in ARM deframer
• X300: Enable BasicRX to use A/B/AB/BA muxing setups, more consistent logging, fix enumeration issue with TwinRX
• USRP2/N2x0: Re-add ability to modulate in the DAC, improve ISE settings to better meet timing
• B205mini: Fix global reset, improve timing in b205_ref_pll
• UHD: Remove a lot of Boost usage, mostly replaced by C++11 features, more unit tests, fix Boost 1.67 compatibility, fix compiler warnings, add API to query clock rate range, fix get_usrp_?x_info
• MPM: Refactored N3xx code, moved C++ standard to 14, refactor Boost.Python bindings, use CMake variable MPM_DEVICE
• Logging: Allow disabling fastpath msgs at runtime
• Docs: Clarified meaning of DSP frequencies, improved manual section on synchronization, added some known issues to B100, USRP2, and USRP1, update test test procedure description
• Examples: Improved benchmark_rate (added failure thresholds, fixed incorrect calculation of samples on drops, fixed timeout values), minor fixes to txrx_loopback_to_file
• Utils: Handle U's in calibration tools, create-lvbitx.py is now Py3k compatible, fixed git-hash.sh
• RFNoC: DDCs/DUCs use DDSes instead of CORDIC, add DMA-based replay block in FPGA, add 64-bit support to axi_wrapper, add compat number to radio block,
• Debian: Fix rules file, fix Changelog format
• Fix license headers
• This release includes all bugfixes and features from previous releases, in particular, the 3.11.* release cycle
• Known issues: N310: In some rare scenarios at high rates, streaming can fail and even bring the FPGA into a bad state.