Add options to the `install()` and `export()` commands to export the
targets we build into Android.mk files that reference them as prebuilt
libraries with associated usage requirements (compile definitions,
include directories, link libraries). This will allow CMake-built
projects to be imported into projects using the Android NDK build
system.
Closes: #15562
When a project is packaged for redistribution the local package
registries should not be updated or consulted. They are for developers.
Add variables to disable use of package registries globally:
* CMAKE_EXPORT_NO_PACKAGE_REGISTRY that disables the export(PACKAGE)
command
* CMAKE_FIND_PACKAGE_NO_PACKAGE_REGISTRY that disables the User Package
Registry in all the find_package calls.
* CMAKE_FIND_PACKAGE_NO_SYSTEM_PACKAGE_REGISTRY that disables the
System Package Registry in all the find_package calls.
Update documentation and unit tests.
Teach the export command to handle export sets defined by invocations
of install(TARGETS ... EXPORT foo). This makes maintenance of targets
exported to both the build tree and install tree trivial.