Update bogofilter to 1.2.5.r1, add new database variants.
There are now -kc and -lmdb slave ports that use
KyotoCabinet and LMDB databases.
Since KyotoCabinet is supposed to relieve TokyoCabinet from duty,
sunset the -tc port some 15 months from now.
Clean up CONFLICTS.
Run self-tests in post-build. This reveals Berkeley DB issues
on the various RISC architectures (mips64, aarch64).