Changes include:
- updates for newer clang-format versions
- Align across comments
- Set C++ version to C++17
- Don't split empty functions, etc.
- Left align reference and pointer operators
- Don't indent name spaces

Split ConstraintInfo class out of Slice.h/cpp

See merge request !2516

Remove use of 'using namespace std'

See merge request !2515

Fix of the RelCU speed-up of ISP

See merge request !2505

Clean up adaptive QP code

See merge request !2510

Clean up RPL-related code

See merge request jvet/VVCSoftware_VTM!2473

Avoid use of std::iterator which is deprecated in C++17

See merge request !2513

Avoid duplicating variables and functions for each reference list

Minor style improvements in AnnexBread

See merge request jvet/VVCSoftware_VTM!2514

Use standardized memory alignment features

See merge request !2509

Minor cleanup for Slice.h

See merge request !2511

Use strong-typed enum for deblocking's EdgeDir

See merge request !2506

Fix and enable SIMD SSE functions

See merge request !2498

Adapt code to new SW guidelines

See merge request !2508

Changes include:
- use [[maybe_unused]] instead of cast to (void)
- use generic lambda function and remove related comment about C++11
- update MSVC version check
- don't condition '#pragma once' on MSVC version

JVET-AC0166: Set C++ version to C++17

See merge request !2507

As decided with software style guide update.

Move GDR status out of PicHeader structure into Picture

See merge request !2501

Virtual boundaries can be set in the encoder config without enabling GDR. The change makes sure, GDR constraints are conditioned on GDR being enabled.

subsumed setMIPFlagISPPass into setBestPredModeDCT2 and removed getBestPredModeDCT2 (because it was unused)

- remove picture header allocations at the encoder
- use correct boundary location in reference pictures after removal of new PH

Should also fix memory allocation issues with PicHeader.

Remove macros from previous meeting cycle

See merge request !2504