Ticket 75 - Port nunc-stans to freebsd.
Bug Description: This is the initial step to port nunc-stans to freebsd. It
builds on the work to decouple lfds from the nuncstans source tree.
Fix Description: This cleans a number of compiler warnings, fixes the pkg
config detection of libevent and cmocka. This also allows optionally building
of the tests suites to avoid a dependency on cmocka if not needed.
https://pagure.io/nunc-stans/issue/75
Author: wibrown
Review by: mreynolds (Thanks!)