It's not yet used by KWin, so we don't need to expose it yet. This gives us more time to fine tune the API.
Auto tests are adjusted to link against the library instead of compiling the source files.
Framework style build system which generates two libraries: * KF5WaylandClient * KF5WaylandServer autotests are adjusted to compile again. They need to be changed to use the libraries once the export header gets generated.
