Map junctions.bed to the Junctions view.

Map junctions.bed to the Junctions view.
Hopefully it'll pass validation and not be treated as a bed file,
even though it ends in the .bed extension.

(There were lots of problems with a previous subission because the
cufflinks bed file was almost but not quite a match to ucsc's bed
file validator. Or maybe they caved on the definition of a score.)