Album Art -- The Quick and Dirty Way.

Album Art -- The Quick and Dirty Way.

If the file 'cover.jpg' exists in $PWD we'll attempt to embed it into
the Oggs and FLACs (sorry, not for MP3 at this stage).

The build script was also updated to ensure that 'install target'
always rebuilds stuff if necessary.

	* album_art: New. A bare-bones script to embed image file into an
	Ogg/Vorbis file.  I didn't write this and I cannot recall where I
	found it.  There is also nothing in the file to indicate who wrote
	it and when.

	* build.sh (_install): Run 'all' if either zcdrip doesn't exist,
	or if zcdrip.in is newer than zcdrip.
	Create the ecdrip symlink in the install directory if either
	$ESHELL is 1, or the symlink exists in the source directory.
	Install 'album_art'.

	* zcdrip.in (Description): "Ogg Vorbis" -> "Ogg/Vorbis".
	Mention cover art.
	(ARTWORK): New. Points to cover art image file.
	(flacenc): Add cover art if $ARTWORK exists.
	(oggrip): Ditto.

Signed-off-by: Steve Youngs <steve@steveyoungs.com>