* Change the minimum cmake version to a range. Uses the new policies of the newer versions if you are on them, taking care of CMP0054.
* Grab a newer version of FindHarfBuzz.cmake from Webkit that fixes the cmake warning the earlier one was giving.
* Add in -ftime-trace as an option on build.sh.
* Precompile PrecompiledHeader.h if you are using cmake 3.16+ and GCC. (Currently disabled on clang due to compilation issues.)
* Check if target_precompile_headers exists rather than by version.
Co-authored-by: scribam <scribam@users.noreply.github.com>