Connect the libucl man page to the build

[allanjude]

Summary

gjb noticed that libucl's man page is not installed.
Most other private libraries also do not install man pages, but this man page may be very useful as we add support for libucl to utilities in base
If we want to avoid users finding this man page, we could name it libprivateucl to match the .so, but I am not sure that makes sense

[gjb]

This is a month old, and has been a bug for a long time. I do not need to be a reviewer to have this fixed.

[allanjude]

this is a private library, so it doesn't need its man page connected.

You can get libucl from ports, and that comes with the man page.