Fixes breakage by commit 1a619522

Don't fail to start if mpd.conf does not exist; just use default
values.

Let the user know that MPD has failed.  Not the best thing to do, but
better than pretending it still runs.

Invoke "ant" when a Java source is modified.

Missing piece from commit e0ca4347

For database plugins that don't use the UpdateService.

They are only used inside dsdiff_read_metadata_extra().

Failure to read another chunk header is not fatal.  Continue to read
metadata.