Update libucl to 0.9.2

[bofh]

Summary

• Add FREEBSD-upgrade instructions
• Add FREEBSD-Xlist file
• Remove all unnecessary files which are not required for in-tree build (discussed with @lwhsu)

Test Plan

In the vendor branch the following were performed:

$ ./autogen.sh
$ ./configure
$ gmake
$ gmake check
$ gmake clean

gmake check passed all tests successfully.

[lwhsu]

I'm neutral to the files under tests/, if they are able to run, installing to /usr/tests/lib/libucl is fine. Since it's part of the base system and we can make sure changing other part of the system doesn't break libucl. Not sure how much work needs for integrating it to the test suite, but it is a possible future work.

[emaste]

I'd recommend we not strip the tests out

[jhb]

Why did you delete ucl++.h? My branch to convert ctld to C++ depend on the C++ bindings to libucl.

[bofh]

Include tests and headers which were dropped earlier.