Make the extra dependencies in DPADD be dependencies of PROG_FULL and
SHLIB_NAME_FULL so that the full binary is relinked when a dependency
changes. Right now the existing full binary is left as-is and only
the objcopy to remove debug symbols is run.

Differential Revision: https://reviews.freebsd.org/D1834
Reviewed by: emaste
MFC after: 3 days