Version 4.5.0

This release has the following changes:

POTENTIALLY BREAKING CHANGES:

• The toolchain was previously optimized to prevent multiple executions during setup. However, this feature has been discontinued due to complications it caused when building nested libraries with multiple targets. If you prefer the previous behavior, you can enable it by adding -DOS_SINGLE_BUILD=YES as an argument to your builds.

Other additions & changes:

• VISIONOSCOMBINED added as a new platform option (Thanks @okwasniewski!)
• MAC_CATALYST_UNIVERSAL added as a new platform option (Thanks @oliverepper!)
• The TVOSCOMBINED platform option added support for the arm64 architecture (Thanks @okwasniewski!)
• As mentioned in the potentially breaking changes, the toolchain will now run for all targets in nested builds, which fixes #146.
  To opt-out of this behavior, add OS_SINGLE_BUILD as an argument when invoking the CMake commands.