* CMake: Remove guards around CMP0043 and CMP0054
We require CMake >= 3.8 which includes the policies.
CMP0043 OLD behaviour is still required by cotire.
(cherry picked from commit 18ad767226)
* CMake: Use target_precompile_headers instead of cotire with CMake >= 3.16.0
(cherry picked from commit f387673aa3)
* Build: Enable and require c++17
* Build: Raise Visual Studio version from 2017 15.2 to 2017 15.9
* Build: Raise GCC version from 6.3.0 to 7.1.0
* Reduce branch differences
* Fix build after latest merge
* Cleanup after latest merge
* Required for handling flags inherited by linked projects
correctly in the corresponding precompiled header.
* Reduces the maintenance effort for precompiled headers
* *PCH.cpp are now only compiled with MSVC, other compilers use custom helper commands to generate the precompiled header
* Don't call the linker for pch helpertargets
(cherry picked from commit 137f5e7887)
* A PCH is still generated for every target which was passed to the macro
* Resolves naming conflicts when using the same PCH header from multiple projects
* Ref #15671
For finding out the "standard" parameters examine the cmake/options.cmake file and adjacent files for your platform/compiler.
For platform settings -> cmake/platform/*/settings.cmake
For compiler settings -> cmake/compiler/*/settings.cmake
Some more testing and changes IS required, but I don't have OSX/XCode to kill off the main issues
--HG--
branch : trunk
rename : cmake/FindPlatform.cmake => cmake/macros/CheckPlatform.cmake
rename : cmake/FindACE.cmake => cmake/macros/FindACE.cmake
rename : cmake/FindMySQL.cmake => cmake/macros/FindMySQL.cmake
rename : cmake/FindOpenSSL.cmake => cmake/macros/FindOpenSSL.cmake
rename : cmake/FindPCHSupport.cmake => cmake/macros/FindPCHSupport.cmake
rename : cmake/FindReadline.cmake => cmake/macros/FindReadline.cmake
rename : cmake/cmake_uninstall.cmake.in => cmake_uninstall.cmake.in
