Eliminate support for partial reads.  The Linux kernel will never
return partial results, so this buffering was unnecessary.

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

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.

Previously, only streams were saved with range and tags, but this is
necessary for all "partial" songs (e.g. CUE tracks).

Manipulates the playback range of a queued song.

Now that Song::GetDuration() is used (which considers start_ms and
end_ms), we don't need to override the Tag's duration value.

Fixes the bogus duration of the last track in a CUE sheet.

Add one method that prints only the tag values, but not the song
duration.

Enables using range-based "for".

Move code from the FAAD decoder plugin.